JP4145529B2 - Optical recording medium and recording method - Google Patents

Description

｛式中、Ｒ¹〜Ｒ⁴は水素原子または任意の置換基を表し、Ｒ¹〜Ｒ⁴の隣接する少なくとも２つの置換基は結合して炭化水素環または複素環構造を形成しても良く、該炭化水素環及び該複素環は、置換基を有していてもよい。Ｘ¹は電子吸引性基を表し、Ｘ²は水素原子または−Ｑ−Ｙを表す。（Ｑは直接結合、炭素数１または２のアルキレン基、アリーレン基またはヘテロアリーレン基を表し、Ｙは電子吸引性基を表す。該アルキレン基、該アリーレン基および該ヘテロアリーレン基はＹ以外に任意の置換基を有していてもよい。）Ｘ³は酸素原子を表す。Ｒ ⁵は水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基、シアノ基、ヒドロキシ基、−ＮＲ⁷Ｒ⁸（Ｒ⁷，Ｒ⁸は各々独立して水素原子、置換されてもよい炭化水素基または置換されてもよい複素環基を表す。）、又は−ＣＯＲ⁹（Ｒ⁹は置換されてもよい炭化水素基または置換されてもよい複素環基を表す。）を表し、Ｒ⁵はＲ⁴と結合して置換されてもよい炭化水素環または置換されてもよい複素環構造を形成しても良い。｝
【０００６】
【化４】

｛式中、Ｒ¹〜Ｒ⁴は水素原子または任意の置換基を表し、Ｒ¹〜Ｒ⁴の隣接する少なくとも２つの置換基は結合して炭化水素環または複素環構造を形成しても良く、該炭化水素環及び該複素環は、置換基を有していてもよい。環Ａは＞Ｃ＝Ｏと共に置換基を有していてもよい炭素環式ケトン環または複素環式ケトン環を表す。
Ｘ³は酸素原子、硫黄原子または＝Ｎ−Ｒ⁶を表す。（Ｒ⁶は水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基、シアノ基、ヒドロキシ基を表す。）
Ｒ⁵は水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基、シアノ基、ヒドロキシ基、−ＮＲ⁷Ｒ⁸（Ｒ⁷，Ｒ⁸は各々独立して水素原子、置換されてもよい炭化水素基または置換されてもよい複素環基を表す。）、又は−ＣＯＲ⁹（Ｒ⁹は置換されてもよい炭化水素基または置換されてもよい複素環基を表す。）を表し、Ｒ⁵はＲ⁴と結合して置換されてもよい炭化水素環または置換されてもよい複素環構造を形成しても良い。｝
【０００７】
【発明の実施の形態】
以下本発明につき詳細に説明する。
本発明の記録層に使用される化合物は、３５０〜５３０nmの青色光領域に適度の吸収を有し、青色レーザーでの記録に適する色素化合物が好ましい。本発明ではかかる色素として、前記一般式[Ｉ]及び[II]によって示される色素化合物が使用される。
以下に前記一般式[Ｉ]及び[II]で表される化合物について説明する。
【０００８】
本発明に係る色素化合物を示す前記一般式[Ｉ]及び[II]において、Ｒ¹〜Ｒ⁴は各々独立に水素原子及び任意の置換基を表し、任意の置換基は、更に置換されていてもよい。該任意の置換基の例としては、次のようなものが例示される。メチル基、エチル基、プロピル基、イソプロピル基、n-ブチル基、sec-ブチル基、tert-ブチル基、n-へプチル基等の置換されてもよい炭素数１〜１８の直鎖又は分岐のアルキル基；シクロプロピル基、シクロペンチル基、シクロヘキシル基、アダマンチル基等の置換されてもよい炭素数３〜１８の環状アルキル基；ビニル基、プロペニル基、ヘキセニル基等の置換されてもよい炭素数２〜１８の直鎖又は分岐のアルケニル基；シクロペンテニル基、シクロヘキセニル基等の置換されてもよい炭素数３〜１８の環状アルケニル基；2-チエニル基、2-ピリジル基、4-ピペリジル基、モルホリノ基等の置換されてもよい複素環基；フェニル基、トリル基、キシリル基、メシチル基等の置換されてもよい炭素数６〜１８のアリール基；ベンジル基、フェネチル基等の置換されてもよい炭素数７〜２０のアラルキル基；メトキシ基、エトキシ基、n-プロポキシ基、イソプロポキシ基、n-ブトキシ基、sec-ブトキシ基、tert-ブトキシ基等の置換されてもよい炭素数１〜１８の直鎖または分岐のアルコキシ基；プロペニルオキシ基、ブテニルオキシ基、ペンテニルオキシ基等の置換されてもよい炭素数３〜１８の直鎖または分岐のアルケニルオキシ基；メチルチオ基、エチルチオ基、n-プロピルチオ基、n-ブチルチオ基、sec-ブチルチオ基、tert-ブチルチオ基等の置換されてもよい炭素数１〜１８の直鎖または分岐のアルキルチオ基が挙げられる。
【０００９】
他の具体例としては、フッ素原子、塩素原子、臭素原子等のハロゲン原子；ニトロ基；ニトロソ基；シアノ基；イソシアノ基；シアナト基；イソシアナト基；チオシアナト基；イソチオシアナト基；メルカプト基；ヒドロキシ基；ヒドロキシアミノ基；ホルミル基；スルホン酸基；カルボキシル基；−ＣＯＲ²⁰で表されるアシル基、−ＮＲ²¹Ｒ²²で表されるアミノ基、−ＮＨＣＯＲ²³で表されるアシルアミノ基、−ＮＨＣＯＯＲ²⁴で表されるカーバメート基、−ＣＯＯＲ²⁵で表されるカルボン酸エステル基、−ＯＣＯＲ²⁶で表されるアシルオキシ基、−ＣＯＮＲ²⁷Ｒ²⁸で表されるカルバモイル基、−ＳＯ₂Ｒ²⁹で表されるスルホニル基、−ＳＯ₂ＮＲ³⁰Ｒ³¹で表されるスルファモイル基、−ＳＯ₃Ｒ³²で表されるスルホン酸エステル基、−ＮＨＳＯ₂Ｒ³³で表されるスルホンアミド基が挙げられる。
【００１０】
これらの置換基の位置は特に限定されず、置換基の数も１〜４個の範囲で可能である。複数の置換基を有する場合、同種でも異なってもよい。
ここでＲ²⁰、Ｒ²³，Ｒ²⁴，Ｒ²⁵，Ｒ²⁶、Ｒ²⁹，Ｒ³²、Ｒ³³は置換されてもよい炭化水素基、または置換されてもよい複素環基を表し、Ｒ²¹、Ｒ²²，Ｒ²⁷，Ｒ²⁸，Ｒ³⁰，Ｒ³¹は水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基のいずれかを表す。
【００１１】
このＲ²⁰〜Ｒ³³で表される炭化水素基とは、メチル基、エチル基、プロピル基、イソプロピル基、n-ブチル基、sec-ブチル基、tert-ブチル基、n-へプチル基等の炭素数１〜１８の直鎖または分岐のアルキル基、シクロプロピル基、シクロペンチル基、シクロヘキシル基、アダマンチル基等の炭素数３〜１８の環状アルキル基、ビニル基、プロペニル基、ヘキセニル基等の炭素数２〜１８の直鎖または分岐のアルケニル基、シクロペンテニル基、シクロヘキセニル基等の炭素数３〜１８の環状アルケニル基、ベンジル基、フェネチル基等の炭素数７〜２０のアラルキル基、フェニル基、トリル基、キシリル基、メシチル基等の炭素数６〜１８アリール基を表す。これらの基のアルキル鎖部分及びアリール基部分は後述するＲ¹〜Ｒ⁴のアルキル鎖部分が有し得る置換基で更に置換されていてもよい。
【００１２】
またＲ²⁰〜Ｒ³³で表される複素環基は、４−ピペリジル基、モルホリノ基、2-モルホリニル基、ピペラジル基等の飽和複素環でも、2-フリル基、2-ピリジル基、2-チアゾリル基、2-キノリル基等の芳香族複素環でもよい。これらは複数のヘテロ原子を含んでいても、さらに置換基を有していてもよく、また結合位置も問わない。複素環として好ましい構造のものは、５〜６員環の飽和複素環、５〜６員環の単環及びその２縮合環の芳香族複素環である。
【００１３】
具体的には、−ＣＯＲ²⁰で表される置換されていてもよいアシル基；−ＮＲ²¹Ｒ²²で表される置換されていてもよいアミノ基；−ＮＨＣＯＲ²³で表される置換されていてもよいアシルアミノ基；−ＮＨＣＯＯＲ²⁴で表される置換されていてもよいカーバメート基；−ＣＯＯＲ²⁵で表される置換されていてもよいカルボン酸エステル基；−ＯＣＯＲ²⁶で表される置換されていてもよいアシルオキシ基；−ＣＯＮＲ²⁷Ｒ²⁸で表される置換されていてもよいカルバモイル基；−ＳＯ₂Ｒ²⁹で表される置換されていてもよいスルホニル基；−ＳＯ₂ＮＲ³⁰Ｒ³¹で表される置換されていてもよいスルファモイル基；−ＳＯ₃Ｒ³²で表される置換されていてもよいスルホン酸エステル基；−ＮＨＳＯ₂Ｒ³³で表される置換されていてもよいスルホンアミド基の各々の好ましい具体例を以下に示す。
【００１４】
アシル基（−ＣＯＲ²⁰）
【化５】

【００１５】
アミノ基（−ＮＲ²¹Ｒ²²）
【化６】

【００１６】
アシルアミノ基（−ＮＨＣＯＲ²³）
【化７】

【００１７】
カーバメート基（−ＮＨＣＯＯＲ²⁴）
【化８】

【００１８】
カルボン酸エステル基（−ＣＯＯＲ²⁵）
【化９】

【００１９】
アシルオキシ基（−ＯＣＯＲ²⁶）
【化１０】

【００２０】
カルバモイル基（−ＣＯＮＲ²⁷Ｒ²⁸）
【化１１】

【００２１】
スルホニル基（−ＳＯ₂Ｒ²⁹）
【化１２】

【００２２】
スルファモイル基（−ＳＯ₂ＮＲ³⁰Ｒ³¹）
【化１３】

【００２３】
スルホン酸エステル基（−ＳＯ₃Ｒ³²）
【化１４】

【００２４】
スルホンアミド基（−ＮＨＳＯ₂Ｒ³³）
【化１５】

【００２５】
Ｒ¹〜Ｒ⁴が示す直鎖又は分岐のアルキル基、環状アルキル基、直鎖または分岐のアルケニル基、環状アルケニル基、直鎖または分岐のアルコキシ基、直鎖または分岐のアルキルチオ基、及びＲ²⁰〜Ｒ³³が示すアルキル基のアルキル鎖部分は、更に置換基を有し得るが、その置換基としては、例えば以下のものが挙げられる。
メトキシ基、エトキシ基、n-プロポキシ基、イソプロポキシ基、n-ブトキシ基、sec-ブトキシ基、tert-ブトキシ基等の炭素数１〜１０のアルコキシ基；メトキシメトキシ基、エトキシメトキシ基、プロポキシメトキシ基、エトキシエトキシ基、プロポキシエトキシ基、メトキシブトキシ基等の炭素数２〜１２のアルコキシアルコキシ基；メトキシメトキシメトキシ基、メトキシメトキシエトキシ基、メトキシエトキシメトキシ基、メトキシエトキシエトキシ基、エトキシエトキシメトキシ基等の炭素数３〜１５のアルコキシアルコキシアルコキシ基；フェノキシ基、トリルオキシ基、キシリルオキシ基、ナフチルオキシ基等の炭素数６〜１２のアリールオキシ基；アリルオキシ基、ビニルオキシ基等の炭素数２〜１２のアルケニルオキシ基等が例示される。
【００２６】
更に、他の置換基として、2-チエニル基、2-ピリジル基、4-ピペリジル基、モルホリノ基等の複素環基；シアノ基；ニトロ基；ヒドロキシル基；アミノ基；Ｎ，Ｎ−ジメチルアミノ基、Ｎ，Ｎ−ジエチルアミノ基等の炭素数１〜１０のアルキルアミノ基；メチルスルホニルアミノ基、エチルスルホニルアミノ基、n-プロピルスルホニルアミノ基等の炭素数１〜６のアルキルスルホニルアミノ基；フッ素原子、塩素原子、臭素原子等のハロゲン原子；メトキシカルボニル基、エトキシカルボニル基、n-プロポキシカルボニル基、イソプロポキシカルボニル基、n-ブトキシカルボニル基等の炭素数２〜７のアルコキシカルボニル基；メチルカルボニルオキシ基、エチルカルボニルオキシ基、n-プロピルカルボニルオキシ基、イソプロピルカルボニルオキシ基、n-ブチルカルボニルオキシ基等の炭素数２〜７のアルキルカルボニルオキシ基；メトキシカルボニルオキシ基、エトキシカルボニルオキシ基、n-プロポキシカルボニルオキシ基、イソプロポキシカルボニルオキシ基、n-ブトキシカルボニルオキシ基等の炭素数２〜７のアルコキシカルボニルオキシ基等が挙げられる。
【００２７】
Ｒ¹〜Ｒ⁴の隣接する少なくとも２つの置換基は結合して炭化水素環または複素環構造を形成することが出来る。隣接する２つの置換基、Ｒ¹とＲ²、Ｒ²とＲ³、Ｒ³とＲ⁴が互いに結合して、各々独立に形成する環は、飽和または不飽和の炭化水素環でも、ヘテロ原子を一つまたは複数個含む飽和または不飽和の複素環でもよく、環状構造は単環でも縮合環でもよい。環の員数は特に制限されないが、炭化水素環、複素環共に好ましいのは５〜７員環で、特に好ましいのは５〜６員環である。また、隣接する３つの置換基、例えば、Ｒ¹〜Ｒ³、Ｒ²〜Ｒ⁴が互いに結合して縮合環を形成しても良い。
これらが示す好ましい環状構造を下記に示す。
【００２８】
【化１６】

（上記環構造において、Ｄ¹〜Ｄ³は任意の置換基を表す。）
Ｄ¹〜Ｄ³の任意の置換基としては、Ｒ¹〜Ｒ⁴のアルキル鎖部分が有し得る置換基が挙げられる。Ｄ¹〜Ｄ³として好ましくは、水素原子、アルキル基、アリール基、アラルキル基、ヒドロキシ基、アルコキシ基が挙げられる。
また上記環状構造の環は前述したような置換または未置換のアルキル基で置換されていてもよい。このアルキル基が有し得る置換基としては、例えば、前記Ｒ¹〜Ｒ⁴のアルキル鎖部分が有し得る置換基と同種のものが挙げられる。
【００２９】
Ｒ¹〜Ｒ⁴で表される置換基として好ましいものは、置換されてもよい炭素数１〜１２の直鎖または分岐のアルキル基、置換されてもよい炭素数３〜１２の環状アルキル基、置換されてもよい炭素数２〜１２の直鎖または分岐のアルケニル基、５〜６員環の飽和複素環基、５〜６員環の単環または２縮合環の複素芳香環基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい炭素数７〜２０のアラルキル基、置換されてもよい炭素数１〜１２の直鎖または分岐のアルコキシ基、置換されてもよい炭素数１〜１２の直鎖または分岐のアルキルチオ基、ハロゲン原子、ニトロ基、シアノ基、メルカプト基、ヒドロキシ基、−ＣＯＲ²⁰で表されるアシル基、−ＮＲ²¹Ｒ²²で表されるアミノ基、−ＮＨＣＯＲ²³で表されるアシルアミノ基、−ＮＨＣＯＯＲ²⁴で表されるカーバメート基、−ＣＯＯＲ²⁵で表されるカルボン酸エステル基、−ＯＣＯＲ²⁶で表されるアシルオキシ基、−ＣＯＮＲ²⁷Ｒ²⁸で表されるカルバモイル基、−ＮＨＳＯ₂Ｒ³³で表されるスルホンアミド基が挙げられ、Ｒ¹とＲ²、Ｒ²とＲ³、Ｒ³とＲ⁴が環を形成する場合は、置換されていてもよい５〜６員環の炭化水素環、あるいは置換されていてもよい５〜６員環の複素環が好ましい。
【００３０】
中でもＲ¹〜Ｒ⁴で表される置換基として特に好ましいものは、炭素数１〜１２の置換されてもよい直鎖または分岐のアルキル基、炭素数３〜１８の置換されてもよい環状アルキル基、炭素数１〜１２の置換されてもよい直鎖または分岐のアルコキシ基、５〜６員環の飽和複素環基、５〜６員環の複素芳香環基、炭素数６〜１８のアリール基、炭素数７〜２０のアラルキル基、炭素数１〜１２の置換されてもよい直鎖または分岐のアルキルチオ基、ハロゲン原子、ニトロ基、ヒドロキシ基、−ＣＯＲ²⁰で表されるアシル基、−ＯＣＯＲ²⁶で表されるアシルオキシ基、−ＮＲ²¹Ｒ²²で表されるアミノ基、−ＣＯＯＲ²⁵で表されるカルボン酸エステル基、−ＣＯＮＲ²⁷Ｒ²⁸で表されるカルバモイル基、−ＮＨＳＯ₂Ｒ³³で表されるスルホンアミド基であり、Ｒ¹とＲ²、Ｒ²とＲ³、Ｒ³とＲ⁴が環を形成する場合は、これらのいずれか一つがベンゼン環構造を形成する場合である。
【００３１】
前記一般式[Ｉ]及び[II]においてＲ⁵は、水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基、シアノ基、ヒドロキシ基、−ＮＲ⁷Ｒ⁸、−ＣＯＲ⁹のいずれかを表す。
Ｒ⁵で表される置換されてもよい炭化水素基としては、メチル基、エチル基、プロピル基、イソプロピル基、n-ブチル基、sec-ブチル基、tert-ブチル基、n-へプチル基等の炭素数１〜１８の直鎖または分岐のアルキル基、シクロプロピル基、シクロペンチル基、シクロヘキシル基、アダマンチル基等の炭素数３〜１８の環状アルキル基、ビニル基、プロペニル基、ヘキセニル基等の炭素数２〜１８の直鎖または分岐のアルケニル基、シクロペンテニル基、シクロヘキセニル基等の炭素数３〜１８の環状アルケニル基、ベンジル基、フェネチル基等の炭素数７〜２０のアラルキル基、フェニル基、トリル基、キシリル基、メシチル基等の炭素数６〜１８アリール基を表す。これらの基のアルキル鎖部分及びアリール基部分は前述したＲ¹〜Ｒ⁴のアルキル鎖部分が有し得る置換基で更に置換されていてもよい。
【００３２】
Ｒ⁵で表される置換されてもよい複素環基としては、４−ピペリジル基、モルホリノ基、2-モルホリニル基、ピペラジル基等の飽和複素環でも、2-フリル基、2-ピリジル基、2-チアゾリル基、2-キノリル基等の芳香族複素環でもよい。これらは複数のヘテロ原子を含んでいても、さらに置換基を有していてもよく、また結合位置も問わない。複素環として好ましい構造のものは、５〜６員環の飽和複素環、５〜６員環の単環及びその２縮合環の芳香族複素環である。
Ｒ⁵が置換されてもよい炭化水素基としてアルキル鎖を有する場合、Ｒ⁴と結合して、飽和または不飽和の炭化水素環や、飽和または不飽和の複素環構造を形成してもよく、環状構造は単環でも縮合環でもよい。環状構造の員数は特に制限されないが、炭化水素環、複素環共に好ましいのは５〜６員環である。これらの好ましい環状構造を下記に示す。
【００３３】
【化１７】

【００３４】
Ｒ⁵で表される−ＮＲ⁷Ｒ⁸のＲ⁷、Ｒ⁸は、各々独立に水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基のいずれかを表す。
Ｒ⁷、Ｒ⁸としては、Ｒ⁵として例示した炭化水素基および複素環基と同様の基が挙げられるが、好ましくは、水素原子、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数７〜２０のアラルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい複素環基である。
Ｒ⁵で表される−ＣＯＲ⁹におけるＲ⁹は、置換されてもよい炭化水素基、置換されてもよい複素環基のいずれかを表し、好ましくは炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数７〜２０のアラルキル基、置換されてもよい炭素数６〜２０のアリール基である。以下に好ましいＲ⁵の例を示す。
【００３５】
【化１８】

【００３６】
【化１９】

【００３７】
前記一般式[Ｉ]においてＸ ³ は酸素原子を表し、[II]においてＸ³は、酸素原子、硫黄原子または＝Ｎ−Ｒ⁶のいずれかを表す。Ｘ³で表される＝Ｎ−Ｒ⁶におけるＲ⁶は、水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基、シアノ基、ヒドロキシ基のいずれかを表し、好ましくは炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数７〜２０のアラルキル基、置換されてもよい炭素数６〜２０のアリール基である。これらの基が有し得る置換基としては、前述のＲ¹〜Ｒ⁴のアルキル鎖が有し得る置換基におけると同種のものを挙げることが出来る。
【００３８】
前記一般式[Ｉ]において、Ｘ¹は電子吸引性基を表し、Ｘ²は水素原子、または−Ｑ−Ｙを表す。ここでＱは連結基を表し、炭素数１または２のアルキレン基、アリーレン基、ヘテロアリーレン基を表すか、これらの連結基を介さずに直接Ｙに結合する、つまり、直接結合を表す。ＹとＸ¹とは独立に電子吸引性基を表す。
【００３９】
Ｘ¹、Ｙが表す電子吸引性基はとしては、一般にハメット則においてシグマ定数σ（σm及びσp、特にσp）が正の値を持つものが挙げられる。これらの例としては、シアノ基、ニトロ基、ニトロソ基、ハロゲン原子、カルボキシル基、ホルミル基、アシル基、カルボン酸エステル基、カルバモイル基、トリアルキルアミノ基、トリフルオロメチル基等のハロゲン置換アルキル基、スルホン酸基、スルホン酸エステル基、スルホニル基、スルファモイル基、スルフィニル基等が挙げられる。
これらのＸ¹、Ｙの表す電子吸引性基として好ましいものとしては、シアノ基、ニトロ基、ハロゲン置換アルキル基、−ＣＯＲ¹⁰で表されるアシル基、−ＣＯＯＲ¹¹で表されるカルボン酸エステル基、−ＣＯＮＲ¹²Ｒ¹³で表されるカルバモイル基、−ＳＯＲ¹⁶で表されるスルフィニル基、−ＳＯ₂Ｒ¹⁷で表されるスルホニル基、−ＳＯ₂ＮＲ¹⁸Ｒ¹⁹で表されるスルファモイル基である。
【００４０】
−ＣＯＲ¹⁰で表されるアシル基のＲ¹⁰は、置換されてもよい炭化水素基、置換されてもよい複素環基のいずれかを表し、これらの中でＲ¹⁰として好ましいものは、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数７〜２０のアラルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい５〜７員環の飽和複素環、置換されてもよい５〜６員環の単環及びその２縮合環の複素芳香環である。具体的には、アセチル基、プロピオニル基、イソバレリル基、ピバロイル基、ベンゾイル基、２−テノイル基、２−フロイル基、シクロヘキサノイル基等のアシル基が挙げられる。
【００４１】
−ＣＯＯＲ¹¹で表されるカルボン酸エステル基のＲ¹¹は置換されてもよい炭化水素基、置換されてもよい複素環基を表し、好ましくは、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい炭素数７〜２０のアラルキル基、５〜７員環の飽和複素環、置換されてもよい５〜６員環の単環及びその２縮合環の複素芳香環である。具体的には、メトキシカルボニル基、エトキシカルボニル基、イソブトキシカルボニル基、フェノキシカルボニル基、シクロヘキシルオキシカルボニル基、２−ピリジルオキシカルボニル基等のカルボン酸エステル基が挙げられる。
【００４２】
−ＣＯＮＲ¹²Ｒ¹³で表されるカルバモイル基のＲ¹²，Ｒ¹³は各々独立に水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基、置換されてもよいアミノ基、置換されてもよいアシルアミノ基、置換されてもよいカーバメート基、−ＣＯＲ¹⁴、−ＣＯＯＲ¹⁵を表す。ここでＲ¹⁴，Ｒ¹⁵は任意の置換基を表し、好ましい置換基としては、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよいアミノ基である。
【００４３】
Ｒ¹²，Ｒ¹³として好ましいものとしては、水素原子、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい炭素数７〜２０のアラルキル基、５〜７員環の飽和複素環、置換されてもよい５〜６員環の単環及びその２縮合環の複素芳香環、置換されてもよいアミノ基、−ＣＯＲ¹⁴、−ＣＯＯＲ¹⁵があげられる。
以下に−ＣＯＮＲ¹²Ｒ¹³で表されるカルバモイル基の構造を示す。
【００４４】
【化２０】

【００４５】
−ＳＯＲ¹⁶で表されるスルフィニル基のＲ¹⁶は、置換されてもよい炭化水素基、置換されてもよい複素環基を表し、好ましいものとしては、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい炭素数７〜２０のアラルキル基、５〜７員環の飽和複素環、置換されてもよい５〜６員環の単環及びその２縮合環の複素芳香環である。具体的には、以下に示すスルフィニル基等が挙げられる。
【００４６】
【化２１】

【００４７】
−ＳＯ₂Ｒ¹⁷で表されるスルホニル基のＲ¹⁷は、置換されてもよい炭化水素基、置換されてもよい複素環基を表し、好ましいものとしては、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい炭素数７〜２０のアラルキル基、５〜７員環の飽和複素環、置換されてもよい５〜６員環の単環及びその２縮合環の複素芳香環である。具体的には、以下に示すスルホニル基等が挙げられる。
【００４８】
【化２２】

【００４９】
−ＳＯ₂ＮＲ¹⁸Ｒ¹⁹で表されるスルファモイル基のＲ¹⁸，Ｒ¹⁹は水素原子、置換されてもよい炭化水素基、置換されてもよい複素環基を表し、好ましいものとしては、水素原子、置換されてもよい炭素数１〜１８の直鎖または分岐のアルキル基、置換されてもよい炭素数６〜１８のアリール基、置換されてもよい炭素数７〜１８のアラルキル基、５〜７員環の飽和複素環、置換されてもよい５〜６員環の単環及びその２縮合環の複素芳香環である。具体的には、以下に示すスルファモイル基等が挙げられる。
【００５０】
【化２３】

【００５１】
上記Ｒ¹⁰〜Ｒ¹⁹で表される置換されてもよい炭化水素基、置換されてもよい複素環基としては、具体的には前記Ｒ²⁰〜Ｒ³³におけると同様な基を挙げることができる。
Ｑで表される連結基は、直接結合又は炭素数１〜２のアルキレン基、アリーレン基、ヘテロアリーレン基を表し、アルキレン基の場合、炭素原子は水素原子以外に前述のアルキル鎖が有し得る置換基を有していても、そこから分岐したアルキル鎖を有していてもよい。
Ｑが６員環のアリーレン基、ヘテロアリーレン基を表す場合、電子吸引性基Ｙが結合部に対してオルト位かパラ位にあることが好ましく、５員環のヘテロアリーレン基である場合は、結合部と電子吸引性基が、２位と４位にあることが好ましい。またこれら連結基に結合するＹは複数個でもよい。またＹが結合している以外の箇所に置換基を有していてもよい。
これらの連結基と電子吸引性基の好ましい結合を下記に図示する。
【００５２】
【化２４】

【００５３】
（図中Ｇ¹〜Ｇ⁶は任意の置換基を表し、Ｙは電子吸引性基を示す。）
Ｇ¹〜Ｇ⁶として好ましくは、ニトロ基、シアノ基、アミノ基、ハロゲン原子、ヒドロキシ基、アルコキシ基、アルキルチオ基、アシル基、アリール基、アラルキル基、アシルアミノ基、およびアルコキシカルボニル基が挙げられる。
【００５４】
前記一般式[II]において、環Ａは＞Ｃ＝Ｏと共に炭素環式ケトン構造または複素環式ケトン構造を表す。炭素環式ケトン、複素環式ケトンとは、不飽和または芳香環系の環内の−ＣＨ₂−や＝ＣＨ−が、＞Ｃ＝Ｏに置き換わったものである。また点線で示した環Ａの環構造部にも、複数の＞Ｃ＝Ｏ、＞Ｃ＝Ｓや＞Ｃ＝ＮＨ等を有していてもよい。
環Ａが形成する炭素環式ケトン構造や複素環式ケトン構造は、飽和でも不飽和でもよく、環の員数も特に問わない。また複素環においてはヘテロ原子の数も特に問わない。また環内の炭化水素基部や環を構成する−ＮＨ−の水素原子は、任意の置換基（特にアルキル基やアリール基が好ましい）で置換されていてもよい。
これらの炭素環式ケトン構造や複素環式ケトン構造は、環の一部に更なる環が縮合して、縮合環構造を形成してもよい。該環式ケトン構造に縮合する環構造は、炭化水素環、複素環を問わないが、好ましくは、ベンゼン環または５〜６員環の複素芳香環である。
以下に、該環式ケトンが示す構造を図示する。
【００５５】
【化２５】

【００５６】
環Ａが形成する炭素環式ケトン構造と複素環式ケトン構造の好ましい例としては、５〜６員環の飽和炭化水素環、５〜６員環の飽和または不飽和の複素環のものである。
一般式[Ｉ]、[II]で表される化合物は、その分子量が、好ましくは１０００以下、特に好ましくは７００以下の化合物である。
一般式[Ｉ]、[II]で表される化合物の好ましい例として下記のものが挙げられる。
【００５７】
【化２６】

【００５８】
【化２７】

【００５９】
【化２８】

【００６０】
【化２９】

【００６１】
これら本発明の上記一般式［Ｉ］，［II］で示される化合物からなる色素は、例えば該色素を含む溶液から記録層の成膜を形成する際の、薄膜形成性に優れているので、光学記録媒体の記録層に使用する色素として極めて有用である。また本発明の色素は、該色素を含有する記録層がより短い波長（350nm〜500nm）領域にレーザー光による記録再生に適した強度の吸収を有しているため、短波長レーザーに対応する記録再生用光学記録媒体に使用する色素として、極めて有用である。
【００６２】
本発明の光学記録媒体は、基本的には基板と前記色素化合物を含む記録層とから構成されるものであるが、さらに必要に応じて基板上に下引き層、反射層、保護層等を設けても良い。
好ましい層構成の一例としては、基板上に記録層を設け、該記録層上に金、銀、アルミニウムのような金属反射層および保護層を設けた高反射率の媒体が挙げられる。以下、この構造の媒体を例に、本発明の光学記録媒体について説明する。
【００６３】
本発明の光学記録媒体における基板の材質としては、基本的には記録光及び再生光の波長に対し透明であればよい。
このような材質としては、例えばアクリル系樹脂、メタクリル系樹脂、ポリカーボネート樹脂、ポリオレフィン系樹脂（特に非晶質ポリオレフィン）、ポリエステル系樹脂、ポリスチレン樹脂、エポキシ樹脂等の樹脂からなるもの、ガラスからなるもの、ガラス上に光硬化性樹脂等の放射線硬化性樹脂からなる樹脂層を設けたもの等を使用することができる。
【００６４】
高生産性、コスト、耐吸湿性などの点からは、射出成型ポリカーボネートが好ましく、耐薬品性、耐吸湿性などの点からは、非晶質ポリオレフィンが好ましい。また高速応答などの点からは、ガラス基板が好ましい。
記録層に接して樹脂基板または樹脂層を設け、その樹脂基板または樹脂層上に記録再生光の案内溝やピットを有していてもよい。案内溝がスパイラル状の場合、この溝ピッチが0.2〜1.2μｍ程度であることが好ましい。
【００６５】
基板上、または必要に応じて下引き層を設けた上に、本発明の化合物を含む記録層を形成する。
記録層の成膜方法としては、真空蒸着法、スパッタリング法、ドクターブレード法、キャスト法、スピンコート法、浸漬法等一般に行われている薄膜形成法が挙げられる。量産性、コスト面からはスピンコート法が好ましい。また、厚みの均一な記録層が得られるという点からは、塗布法よりも真空蒸着法等の方が好ましい。
スピンコート法による成膜の場合、回転数は500〜15000rpmが好ましく、スピンコートの後、場合によっては加熱あるいは溶媒蒸気にあてる等の処理を行っても良い。
【００６６】
ドクターブレード法、キャスト法、スピンコート法、浸漬法等の塗布方法により記録層を形成する場合の塗布溶媒としては、基板を侵さない溶媒であればよく、特に限定されない。例えば、ジアセトンアルコール、3-ヒドロキシ-3-メチル-2-ブタノン等のケトンアルコール系溶媒；メチルセロソルブ、エチルセロソルブ等のセロソルブ系溶媒；n-ヘキサン、n-オクタン等の鎖状炭化水素系溶媒；シクロヘキサン、メチルシクロヘキサン、エチルシクロヘキサン、ジメチルシクロヘキサン、n-ブチルシクロヘキサン、tert-ブチルシクロヘキサン、シクロオクタン等の環状炭化水素系溶媒；テトラフルオロプロパノール、オクタフルオロペンタノール、ヘキサフルオロブタノール等のフルオロアルキルアルコール系溶媒；乳酸メチル、乳酸エチル、２−ヒドロキシイソ酪酸メチル等のヒドロキシカルボン酸エステル系溶媒；２−ジメチルアミノエタノール、２−ジエチルアミノエタノール等のアミノ置換アルコール系溶媒等が挙げられる。
【００６７】
真空蒸着法の場合は、例えば本発明の化合物と、必要に応じて他の色素や各種添加剤等の記録層成分を、真空容器内に設置されたるつぼに入れ、真空容器内を適当な真空ポンプで１０^-2〜１０^-5Ｐａ程度にまで排気した後、るつぼを加熱して記録層成分を蒸発させ、るつぼと向き合って置かれた基板上に蒸着させることにより、記録層を形成する。
【００６８】
また、記録層は、記録層の安定や耐光性向上のために、一重項酸素クエンチャーとして遷移金属キレート化合物（例えば、アセチルアセトナートキレート、ビスフェニルジチオール、サリチルアルデヒドオキシム、ビスジチオ−α-ジケトン等）等や、記録感度向上のために金属系化合物等の記録感度向上剤を含有していても良い。ここで金属系化合物とは、遷移金属等の金属が原子、イオン、クラスター等の形で化合物に含まれるものを言い、例えばエチレンジアミン系錯体、アゾメチン系錯体、フェニルヒドロキシアミン系錯体、フェナントロリン系錯体、ジヒドロキシアゾベンゼン系錯体、ジオキシム系錯体、ニトロソアミノフェノール系錯体、ピリジルトリアジン系錯体、アセチルアセトナート系錯体、メタロセン系錯体、ポルフィリン系錯体のような有機金属化合物が挙げられる。金属原子としては特に限定されないが、遷移金属であることが好ましい。
【００６９】
さらに、必要に応じて他系統の色素を併用することもできる。他系統の色素としては、主として記録用のレーザー波長域に適度な吸収を有するものであればよく、特に制限されない。また、CD-Rのような770〜830nmから選ばれた波長の近赤外レーザーやDVD-Rのような620〜690nmから選ばれた赤色レーザーでの記録に適する色素を併用して、複数の波長域でのレーザー光による記録に対応する光学記録媒体とすることもできる。
他系統の色素としては含金属アゾ系色素、フタロシアニン系色素、ナフタロシアニン系色素、シアニン系色素、アゾ系色素、スクアリリウム系色素、含金属インドアニリン系色素、トリアリールメタン系色素、メロシアニン系色素、アズレニウム系色素、ナフトキノン系色素、アントラキノン系色素、インドフェノール系色素、キサンテン系色素、オキサジン系色素、ピリリウム系色素等が挙げられる。
【００７０】
さらに、必要に応じて、バインダー、レベリング剤、消泡剤等を併用することもできる。好ましいバインダーとしては、ポリビニルアルコール、ポリビニルピロリドン、ニトロセルロース、酢酸セルロース、ケトン系樹脂、アクリル系樹脂、ポリスチレン系樹脂、ウレタン系樹脂、ポリビニルブチラール、ポリカーボネート、ポリオレフィン等が挙げられる。
記録層の膜厚は、記録方法などに応じて適した膜厚が異なる為、特に限定するものではないが、通常50〜300nmである。
【００７１】
記録層の上には、反射層を形成してもよく、その膜厚は好ましくは、厚さ50〜300nmである。反射層の材料としては、再生光の波長で反射率の十分高いもの、例えば、Au、Al、Ag、Cu、Ti、Cr、Ni、Pt、Ta、Cr及びPdの金属を単独あるいは合金にして用いることが可能である。この中でもAu、Al、Agは反射率が高く反射層の材料として適している。これらを主成分とする以外に他成分として下記のものを含んでいても良い。他成分の例としては、Mg、Se、Hf、Ｖ、Nb、Ru、Ｗ、Mn、Re、Fe、Co、Rh、Ir、Cu、Zn、Cd、Ga、In、Si、Ge、Te、Pb、Po、Sn、Bi、Nd、Ta、Ti、Pt、Pdなどの金属及び半金属を挙げることができる。なかでもAgを主成分としているものはコストが安い点、高反射率が出やすい点、更に後で述べる印刷受容層を設ける場合には地色が白く美しいものが得られる点等から特に好ましい。ここで主成分とは含有率が５０％以上のものをいう。
【００７２】
金属以外の材料で低屈折率薄膜と高屈折率薄膜を交互に積み重ねて多層膜を形成し、反射層として用いることも可能である。
反射層を形成する方法としては、例えば、スパッタ法、イオンプレーティング法、化学蒸着法、真空蒸着法等が挙げられる。また、基板の上や反射層の下に反射率の向上、記録特性の改善、密着性の向上等のために公知の無機系または有機系の中間層、接着層を設けることもできる。
反射層の膜厚は通常４０〜２００ｎｍ程度である。
【００７３】
反射層の上に形成する保護層の材料としては、反射層を外力から保護するものであれば特に限定されない。有機物質の材料としては、熱可塑性樹脂、熱硬化性樹脂、電子線硬化性樹脂、ＵＶ硬化性樹脂等を挙げることができる。また、無機物質としては、酸化ケイ素、窒化ケイ素、ＭｇＦ₂、ＳｎＯ₂等が挙げられる。
熱可塑性樹脂、熱硬化性樹脂などは適当な溶剤に溶解して塗布液を調製し、これを塗布、乾燥することによって形成することができる。ＵＶ硬化性樹脂は、そのままもしくは適当な溶剤に溶解して塗布液を調製した後にこの塗布液を塗布し、ＵＶ光を照射して硬化させることによって形成することができる。ＵＶ硬化性樹脂としては、例えば、ウレタンアクリレート、エポキシアクリレート、ポリエステルアクリレートなどのアクリレート系樹脂を用いることができる。これらの材料は単独であるいは混合して用いても良いし、１層だけではなく多層膜にして用いても良い。
【００７４】
保護層の形成方法としては、記録層と同様にスピンコート法やキャスト法等の塗布法やスパッタ法や化学蒸着法等の方法が用いられるが、この中でもスピンコート法が好ましい。
保護層の膜厚は、一般に0.1〜100μmの範囲であるが、本発明においては、３〜30μmが好ましい。
【００７５】
以上の説明は、基板／記録層／反射層／保護層の順に積層された基本的層構成を有し、該基板を通して照射されたレーザー光により記録・再生を行う光学記録媒体を例に行ったが、本発明の特性を損なわない限り、これら各層の間には任意の層を有していてもよい。
また保護層の上に、あるいは保護層を設けず反射層の上に、接着剤層などを介して更に基板を貼り合わせてもよい。該基板は、何ら層を設けていない基板そのものであっても良く、貼り合わせ面またはその反対面に任意の層を有するものでもよい。少なくとも記録層を有する基板を２枚用意し、該記録層が対向するように貼り合わせることにより、両面につき記録・再生可能な光学記録媒体としてもよい。
【００７６】
更に、本発明の光学記録媒体は、基板／反射層／記録層／保護被膜を順次積層してなる基本的層構成を有し、該保護被膜を通して照射されたレーザー光により記録・再生を行うものであってもよい。この保護被膜は、フィルムないしシート状のものを接着剤によって貼り合わせてもよいし、あるいは前述の保護層と同様に、成膜用の塗液を塗布することにより形成しても良い。このような基本的層構成の場合も、上記各層間には、本発明の特性を損なわない限り、任意の層を有していてもよい。
【００７７】
ところで、光学記録媒体の記録密度を上げるための一つの手段として、対物レンズの開口数を上げて情報記録面に集光される光スポットを微少化することが提案されているが、対物レンズの開口数を上げるとディスクの反り等の影響により集光される光スポットの収差が大きくなり、良好な記録再生信号が安定して得られないという問題が存在する。
このような、媒体の反りによって発生する前記収差を小さくするためには、例えば基板／記録層／反射層／保護層の順に積層された基本的層構成を有し、記録・再生用レーザー光が通過する透明基板の厚みを、0.1mm程度まで薄くするか、基板／反射層／記録層／保護被膜を順次積層してなる光学記録媒体に対し、保護被膜を通して記録・再生することが好ましい。保護被膜の厚みは、通常0.1μｍ〜0.3mm程度、好ましくは0.1μｍ〜200μｍ程度である。
上記いずれの順に積層した媒体においても、必要に応じて、記録・再生光の入射面ではない面に、インクジェット、感熱転写等の各種プリンタ、或いは各種筆記具にて記入（印刷）が可能な印刷受容層を設けてもよい。
【００７８】
本発明の光学記録媒体について使用されるレーザー光は、高密度記録のため波長は短いほど好ましいが、特に350〜530nmのレーザー光が好ましい。かかるレーザー光の代表例としては、中心波長405nm、410nm、515nmのレーザー光が挙げられる。
波長350〜530nmの範囲のレーザー光の一例は、405nm、410nmの青色または515nmの青緑色の高出力半導体レーザーを使用することにより得ることができるが、その他、例えば、(a)基本発振波長が740〜960nmの連続発振可能な半導体レーザー、または(b)半導体レーザーによって励起され、且つ基本発振波長が740〜960nmの連続発振可能な固体レーザーのいずれかを第二高調波発生素子(SHG)により波長変換することによっても得ることができる。
【００７９】
上記のＳＨＧとしては、反転対称性を欠くピエゾ素子であればいかなるものでもよいが、ＫＤＰ、ＡＤＰ、ＢＮＮ、ＫＮ、ＬＢＯ、化合物半導体などが好ましい。第二高調波の具体例としては、基本発振波長が860nmの半導体レーザーの場合、その倍波の430nm、また半導体レーザー励起の固体レーザーの場合は、CrドープしたLiSrAlF₆結晶（基本発振波長860nm）からの倍波の430nmなどが挙げられる。
【００８０】
上記のようにして得られた本発明の光学記録媒体への記録は、基板の両面または片面に設けた記録層に0.4〜0.6μm程度に集束したレーザー光を照射することにより行う。レーザー光の照射された部分には、レーザー光エネルギーの吸収による分解、発熱、溶解等の記録層の熱的変形が起こり、光学特性が変化する。
記録された情報の再生は、レーザー光により、光学特性の変化が起きている部分と起きていない部分の反射率の差を読みとることにより行う。
【００８１】
【実施例】
以下本発明を実施例により更に具体的に説明するが、本発明はその要旨を超えない限り、これら実施例によって限定されるものではない。
[合成例]
前記一般式[Ｉ]、[II]で示される化合物の合成法は特に限定されるものではないが、一般的な製法としては、Tetrahedron,Vol.23(1967),p901やJ. Indian Chem. Soc., Vol.67(1990),p490に記載されているように、イサチン誘導体を、活性メチレンを有する化合物と反応させることによって得られることが知られている。
【００８２】
実施例１
（ａ）製造例
イサチン２．９４ｇ（２０ｍｍｏｌ）とシアノ酢酸エチルエステル２．４９ｇ（２２ｍｍｏｌ）をエタノール２０ｍｌに攪拌溶解させ、ピペリジン２滴を加え、油浴中で４時間還流した。反応溶液は室温まで冷却後、析出した固体を濾過して、固形物を濾別し、例示化合物（１）で表される化合物３．９３ｇ（収率８１．１％）が得られた。
この化合物のクロロホルム中での最大吸収波長(λmax)は３３８．５nm、モル吸光係数は１１，１００であった。
【００８３】
（ｂ）記録媒体例
前述の例示化合物（１）をオクタフルオロペンタノールに溶解し、1.0wt%に調製した。これをろ過してできた溶解液を直径120mm、厚さ1.2mmの射出成型ポリカーボネート樹脂基板上に滴下し、スピナー法により塗布し、塗布後、１００℃で３０分間乾燥した。この塗布膜の最大吸収波長（λmax）は、３３９．０nmであった。
【００８４】
実施例２
（ａ）製造例
５−ニトロイサチン１．９２ｇ（１０ｍｍｏｌ）とシアノ酢酸エチルエステル１．２４ｇ（１１ｍｍｏｌ）をエタノール１０ｍｌに攪拌溶解させ、ピペリジン１滴を加え、油浴中で４時間還流した。反応溶液は室温まで冷却後、析出した固体を濾過して、固形物を濾別し、例示化合物（２）で表される化合物２．１４ｇ（収率７４．５％）が得られた。
この化合物のクロロホルム中での最大吸収波長(λmax)は３０７．０nm、モル吸光係数は２１，３００であった。
【００８５】
（ｂ）記録媒体例
前述の例示化合物（２）をオクタフルオロペンタノールに溶解し、1.0wt%に調製した。これをろ過してできた溶解液を直径120mm、厚さ1.2mmの射出成型ポリカーボネート樹脂基板上に滴下し、スピナー法により塗布し、塗布後、１００℃で３０分間乾燥した。この塗布膜の最大吸収波長（λmax）は、３０８nmであった。
【００８６】
実施例３
（ａ）製造例
前述の例示化合物（２）２．４２ｇ（１０ｍｍｏｌ）を無水酢酸１０ｍｌに加え、この溶液を油浴中４時間還流し、室温まで冷却後、水１００ｍｌ中に滴下した。析出した固体を濾別し、例示化合物（４）で表される化合物２．４５ｇ（収率８６％）を得た。
この化合物のクロロホルム中での最大吸収波長(λmax)は３４１．５nm、モル吸光係数は１０，３００であった。
【００８７】
（ｂ）記録媒体例
前述の例示化合物（４）をオクタフルオロペンタノールに溶解し、1.0wt%に調製した。これをろ過してできた溶解液を直径120mm、厚さ1.2mmの射出成型ポリカーボネート樹脂基板上に滴下し、スピナー法により塗布し、塗布後、１００℃で３０分間乾燥した。この塗布膜の最大吸収波長（λmax）は、３４２．０nmであった。
【００８８】
実施例４
（ａ）製造例
イサチン２．９４ｇ（２０ｍｍｏｌ）とマロノニトリル１．４５ｇ（２２ｍｍｏｌ）をエタノール２０ｍｌに攪拌溶解させ、ピペリジン２滴を加え、油浴中で４時間還流した。反応溶液は室温まで冷却後、析出した固体を濾過して、固形物を濾別し、例示化合物（３）で表される化合物３．７８ｇ（収率９６．８％）が得られた。
この化合物のクロロホルム中での最大吸収波長(λmax)は３５１．０nm、モル吸光係数は１３，２００であった。
【００８９】
（ｂ）記録媒体例
前述の例示化合物（３）を乳酸メチルに溶解し、２.0wt%に調製した。これをろ過してできた溶解液を直径120mm、厚さ1.2mmの射出成型ポリカーボネート樹脂基板上に滴下し、スピナー法により塗布し、塗布後、１００℃で３０分間乾燥した。この塗布膜の最大吸収波長（λmax）は、３５１．０nmであった。
【００９０】
実施例５
（ａ）製造例
前述の例示化合物（４）１．９５ｇ（１０ｍｍｏｌ）を無水酢酸１０ｍｌに加え、この溶液を油浴中４時間還流し、室温まで冷却後、水１００ｍｌ中に滴下した。析出した固体を濾別し、例示化合物（５）で表される化合物１．９８ｇ（収率８３．５％）を得た。
この化合物のクロロホルム中での最大吸収波長(λmax)は３５８．０nm、モル吸光係数は１３，１００であった。
【００９１】
（ｂ）記録媒体例
前述の例示化合物（５）をオクタフルオロペンタノールに溶解し、1.0wt%に調製した。これをろ過してできた溶解液を直径120mm、厚さ1.2mmの射出成型ポリカーボネート樹脂基板上に滴下し、スピナー法により塗布し、塗布後、１００℃で３０分間乾燥した。この塗布膜の最大吸収波長（λmax）は、３７１．０nmであった。
【００９２】
上記の如く調製したこの塗布膜上に、例えばスパッタリング法等にて銀膜を成膜して反射層を形成し、更に紫外線硬化型樹脂をスピンコート等にて塗布・ＵＶ照射により硬化させて保護層を形成し、光学記録媒体とすることができる。この光学記録媒体は、塗布膜のλmaxの値より、350nm〜530nmのレーザー、例えば中心波長405nmの半導体レーザーによる記録再生が可能であることが明らかである。
【００９３】
【発明の効果】
本発明の色素化合物を含有する溶液は、短波長のレーザー光による記録・再生に適した吸収を有する塗布膜を形成することが出来、且つ成膜性にも優れているので、本発明化合物を用いた記録層を有する記録媒体は、短波長レーザーに対応する記録・再生用光学記録媒体として有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a write-once optical recording medium and a recording method using an organic dye in a recording layer, and more particularly to a write-once optical recording medium compatible with a blue laser and a recording method on the optical recording medium. .
[0002]
[Prior art]
Currently, various optical recording media such as CD-R / RW, DVD-R / RW, and MO can store a large amount of information and are easily accessible at random. Therefore, external storage in an information processing apparatus such as a computer is possible. Widely recognized and popular as a device. Among these, organic dye-based optical recording media represented by CD-R and DVD-R are considered to have an advantage in that they are inexpensive and easy to manufacture.
Further, it is desired to increase the recording density of the medium by increasing the amount of information handled. In recent years, optical recording media capable of high-density recording and reproduction using a laser having a short oscillation wavelength such as a blue laser that has been developed significantly are being proposed.
[0003]
[Problems to be solved by the invention]
In general, in the case of an optical recording medium marketed as a CD-R or DVD-R, for example, the CD-R is suitable for recording / reproducing with a laser beam having a wavelength of about 780 nm, and the DVD-R has a wavelength of 600 to It is designed to be suitable for recording / reproduction with about 700nm laser light. In such a recording medium suitable for optical recording / reproducing using a laser beam having a relatively long wavelength, there is a problem that when recording / reproducing is performed using a shorter wavelength laser, the reflectance is low and recording / reproducing cannot be performed. have. An object of the present invention is to provide an organic dye-based optical recording medium that can be recorded and reproduced by a blue laser having a shorter wavelength.
[0004]
[Means for Solving the Problems]
As a result of various studies on organic dyes having high sensitivity to blue lasers, the present inventors have used the compounds represented by the above general formulas [I] and [II] in a recording layer of an optical recording medium corresponding to blue lasers. It was found out that the present invention was obtained and the present invention was reached.
That is, the gist of the present invention is that in an optical recording medium provided with a recording layer capable of recording or reproducing information by a laser on a substrate, the recording layer contains a compound represented by the following general formula [I]. Alternatively, an optical recording medium comprising a compound represented by the following general formula [II] and an optical recording comprising recording information on the optical recording medium using a laser beam having a wavelength of 350 nm to 530 nm Lies in the way.
[0005]
[Chemical 3]

    {Where R is¹~ R^FourRepresents a hydrogen atom or an arbitrary substituent, and R¹~ R^FourAt least two substituents adjacent to each other may combine to form a hydrocarbon ring or heterocyclic structure, and the hydrocarbon ring and heterocyclic ring may have a substituent. X¹Represents an electron-withdrawing group and X²Represents a hydrogen atom or -QY. (Q represents a direct bond, an alkylene group having 1 or 2 carbon atoms, an arylene group, or a heteroarylene group, and Y represents an electron-withdrawing group. The alkylene group, the arylene group, and the heteroarylene group are optional in addition to Y. Which may have a substituent of^ThreeIs oxygen fieldChildTo express. R ^FiveIs a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, a hydroxy group, —NR⁷R⁸(R⁷, R⁸Each independently represents a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group. ) Or -COR⁹(R⁹Represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted. ) And R^FiveIs R^FourMay be bonded to form a hydrocarbon ring which may be substituted or a heterocyclic structure which may be substituted. }
[0006]
[Formula 4]

{Where R is¹~ R^FourRepresents a hydrogen atom or an arbitrary substituent, and R¹~ R^FourAt least two substituents adjacent to each other may combine to form a hydrocarbon ring or heterocyclic structure, and the hydrocarbon ring and heterocyclic ring may have a substituent. Ring A represents a carbocyclic ketone ring or heterocyclic ketone ring which may have a substituent together with> C═O.
X^ThreeIs an oxygen atom, a sulfur atom or ═N—R⁶Represents. (R⁶Represents a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, or a hydroxy group. )
R^FiveIs a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, a hydroxy group, —NR⁷R⁸(R⁷, R⁸Each independently represents a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group. ) Or -COR⁹(R⁹Represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted. ) And R^FiveIs R^FourMay be bonded to form a hydrocarbon ring which may be substituted or a heterocyclic structure which may be substituted. }
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
The compound used in the recording layer of the present invention is preferably a dye compound that has appropriate absorption in the blue light region of 350 to 530 nm and is suitable for recording with a blue laser. In the present invention, a dye compound represented by the general formulas [I] and [II] is used as the dye.
The compounds represented by the general formulas [I] and [II] will be described below.
[0008]
In the general formulas [I] and [II] representing the dye compound according to the present invention, R¹~ R^FourEach independently represents a hydrogen atom and an optional substituent, and the optional substituent may be further substituted. Examples of the optional substituent include the following. A straight chain or branched chain having 1 to 18 carbon atoms which may be substituted such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-heptyl group, etc. An alkyl group; a C3-C18 cyclic alkyl group such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, and an adamantyl group; an optionally substituted carbon number such as a vinyl group, a propenyl group, and a hexenyl group A linear or branched alkenyl group of -18; a cyclic alkenyl group having 3 to 18 carbon atoms which may be substituted, such as a cyclopentenyl group, a cyclohexenyl group; a 2-thienyl group, a 2-pyridyl group, a 4-piperidyl group, Heterocyclic group which may be substituted such as morpholino group; aryl group having 6 to 18 carbon atoms which may be substituted such as phenyl group, tolyl group, xylyl group and mesityl group; benzyl group and phenethyl group Aralkyl group having 7 to 20 carbon atoms which may be substituted such as ru group; substitution of methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, etc. A linear or branched alkoxy group having 1 to 18 carbon atoms which may be substituted; a linear or branched alkenyloxy group having 3 to 18 carbon atoms which may be substituted, such as a propenyloxy group, a butenyloxy group or a pentenyloxy group; Examples thereof include a linear or branched alkylthio group having 1 to 18 carbon atoms which may be substituted, such as a methylthio group, an ethylthio group, an n-propylthio group, an n-butylthio group, a sec-butylthio group and a tert-butylthio group.
[0009]
Other specific examples include halogen atoms such as fluorine atom, chlorine atom, bromine atom; nitro group; nitroso group; cyano group; isocyanato group; isocyanato group; isocyanato group; isothiocyanato group; Hydroxyamino group; formyl group; sulfonic acid group; carboxyl group;²⁰An acyl group represented by -NR^{twenty one}R^{twenty two}An amino group represented by the formula: -NHCOR^{twenty three}An acylamino group represented by the formula: -NHCOOR^{twenty four}Carbamate group represented by -COOR^{twenty five}A carboxylate group represented by the formula: -OCOR²⁶An acyloxy group represented by -CONR²⁷R²⁸A carbamoyl group represented by the formula:₂R²⁹A sulfonyl group represented by -SO₂NR³⁰R³¹A sulfamoyl group represented by -SO_ThreeR³²A sulfonate group represented by the formula: -NHSO₂R³³The sulfonamide group represented by these is mentioned.
[0010]
The position of these substituents is not particularly limited, and the number of substituents can be in the range of 1 to 4. When it has a plurality of substituents, it may be the same or different.
Where R²⁰, R^{twenty three}, R^{twenty four}, R^{twenty five}, R²⁶, R²⁹, R³², R³³Represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted;^{twenty one}, R^{twenty two}, R²⁷, R²⁸, R³⁰, R³¹Represents a hydrogen atom, a hydrocarbon group which may be substituted, or a heterocyclic group which may be substituted.
[0011]
This R²⁰~ R³³The hydrocarbon group represented by the formula is a C1-C18 such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-heptyl group and the like. C2-C18 cyclic alkyl group such as linear or branched alkyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, etc., linear chain having 2-18 carbon atoms such as vinyl group, propenyl group, hexenyl group Or a branched alkenyl group such as a branched alkenyl group, a cyclopentenyl group and a cyclohexenyl group, a cycloalkyl group having a carbon number of 3 to 18 such as a benzyl group and a phenethyl group, a phenyl group, a tolyl group, a xylyl group, C6-C18 aryl groups, such as a mesityl group, are represented. The alkyl chain portion and aryl group portion of these groups are R described later.¹~ R^FourFurther, the alkyl chain portion may be further substituted with a substituent.
[0012]
Also R²⁰~ R³³The heterocyclic group represented by the formula can be a 4-piperidyl group, a morpholino group, a 2-morpholinyl group, a piperazyl group, or a saturated heterocyclic ring, a 2-furyl group, a 2-pyridyl group, a 2-thiazolyl group, or a 2-quinolyl group. An aromatic heterocyclic ring such as These may contain a plurality of heteroatoms, may further have a substituent, and may have any bonding position. Preferred structures for the heterocyclic ring are a 5- or 6-membered saturated heterocyclic ring, a 5- or 6-membered monocyclic ring and an aromatic heterocyclic ring thereof.
[0013]
Specifically, -COR²⁰An optionally substituted acyl group represented by: -NR^{twenty one}R^{twenty two}An optionally substituted amino group represented by: -NHCOR^{twenty three}An optionally substituted acylamino group represented by: -NHCOOR^{twenty four}An optionally substituted carbamate group represented by: -COOR^{twenty five}An optionally substituted carboxylic ester group represented by: -OCOR²⁶An optionally substituted acyloxy group represented by: -CONR²⁷R²⁸An optionally substituted carbamoyl group represented by: -SO₂R²⁹An optionally substituted sulfonyl group represented by formula: -SO₂NR³⁰R³¹An optionally substituted sulfamoyl group represented by: -SO_ThreeR³²An optionally substituted sulfonic acid ester group represented by: -NHSO₂R³³Specific preferred examples of each optionally substituted sulfonamide group are shown below.
[0014]
Acyl group (-COR²⁰)
[Chemical formula 5]

[0015]
Amino group (-NR^{twenty one}R^{twenty two})
[Chemical 6]

[0016]
Acylamino group (-NHCOR^{twenty three})
[Chemical 7]

[0017]
Carbamate group (-NHCOOR^{twenty four})
[Chemical 8]

[0018]
Carboxylic acid ester group (-COOR^{twenty five})
[Chemical 9]

[0019]
Acyloxy group (-OCOR²⁶)
[Chemical Formula 10]

[0020]
Carbamoyl group (-CONR²⁷R²⁸)
Embedded image

[0021]
Sulfonyl group (-SO₂R²⁹)
Embedded image

[0022]
Sulfamoyl group (-SO₂NR³⁰R³¹)
Embedded image

[0023]
Sulfonic acid ester group (-SO_ThreeR³²)
Embedded image

[0024]
Sulfonamide group (-NHSO₂R³³)
Embedded image

[0025]
R¹~ R^FourA linear or branched alkyl group, a cyclic alkyl group, a linear or branched alkenyl group, a cyclic alkenyl group, a linear or branched alkoxy group, a linear or branched alkylthio group, and R²⁰~ R³³The alkyl chain portion of the alkyl group represented by can further have a substituent, and examples of the substituent include the following.
Alkoxy groups having 1 to 10 carbon atoms such as methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group; methoxymethoxy group, ethoxymethoxy group, propoxymethoxy Groups, ethoxyethoxy groups, propoxyethoxy groups, methoxybutoxy groups, etc., alkoxyalkoxy groups having 2 to 12 carbon atoms; methoxymethoxymethoxy groups, methoxymethoxyethoxy groups, methoxyethoxymethoxy groups, methoxyethoxyethoxy groups, ethoxyethoxymethoxy groups, etc. An alkoxyalkoxyalkoxy group having 3 to 15 carbon atoms; an aryloxy group having 6 to 12 carbon atoms such as a phenoxy group, a tolyloxy group, a xylyloxy group and a naphthyloxy group; an alkenyl having 2 to 12 carbon atoms such as an allyloxy group and a vinyloxy group Examples include oxy groups Indicated.
[0026]
Further, as other substituents, heterocyclic groups such as 2-thienyl group, 2-pyridyl group, 4-piperidyl group, morpholino group; cyano group; nitro group; hydroxyl group; amino group; N, N-dimethylamino group An alkylamino group having 1 to 10 carbon atoms such as N, N-diethylamino group; an alkylsulfonylamino group having 1 to 6 carbon atoms such as methylsulfonylamino group, ethylsulfonylamino group and n-propylsulfonylamino group; fluorine atom Halogen atoms such as chlorine atom and bromine atom; alkoxycarbonyl groups having 2 to 7 carbon atoms such as methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group and n-butoxycarbonyl group; methylcarbonyloxy Group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group An alkylcarbonyloxy group having 2 to 7 carbon atoms such as a cis group and an n-butylcarbonyloxy group; a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an isopropoxycarbonyloxy group, and an n-butoxycarbonyloxy group And C2-C7 alkoxycarbonyloxy group such as a group.
[0027]
R¹~ R^FourAt least two adjacent substituents can be combined to form a hydrocarbon ring or heterocyclic structure. Two adjacent substituents, R¹And R², R²And R^Three, R^ThreeAnd R^FourThe rings independently bonded to each other may be a saturated or unsaturated hydrocarbon ring or a saturated or unsaturated heterocyclic ring containing one or more heteroatoms, and the cyclic structure may be monocyclic or condensed. It may be a ring. The number of members of the ring is not particularly limited, but a hydrocarbon ring and a heterocyclic ring are preferably 5 to 7 membered rings, particularly preferably 5 to 6 membered rings. Also, three adjacent substituents such as R¹~ R^Three, R²~ R^FourMay combine with each other to form a condensed ring.
A preferred cyclic structure shown by these is shown below.
[0028]
Embedded image

(In the above ring structure, D¹~ D^ThreeRepresents an arbitrary substituent. )
D¹~ D^ThreeAs an optional substituent of R, R¹~ R^FourThe substituent which this alkyl chain part may have is mentioned. D¹~ D^ThreePreferably, a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, a hydroxy group, or an alkoxy group can be used.
The ring of the above cyclic structure may be substituted with a substituted or unsubstituted alkyl group as described above. Examples of the substituent that the alkyl group may have include, for example, the R¹~ R^FourThe same kind as the substituent which the alkyl chain part may have is mentioned.
[0029]
R¹~ R^FourPreferred examples of the substituent represented by formula (1) include an optionally substituted linear or branched alkyl group having 1 to 12 carbon atoms, an optionally substituted cyclic alkyl group having 3 to 12 carbon atoms, and an optionally substituted group. C2-C12 straight chain or branched alkenyl group, 5- to 6-membered saturated heterocyclic group, 5- to 6-membered monocyclic or bi-fused heteroaromatic group, optionally substituted carbon number An aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms which may be substituted, a linear or branched alkoxy group having 1 to 12 carbon atoms which may be substituted, and an alkyl group having 1 to 12 carbon atoms which may be substituted Linear or branched alkylthio group, halogen atom, nitro group, cyano group, mercapto group, hydroxy group, -COR²⁰An acyl group represented by -NR^{twenty one}R^{twenty two}An amino group represented by the formula: -NHCOR^{twenty three}An acylamino group represented by the formula: -NHCOOR^{twenty four}Carbamate group represented by -COOR^{twenty five}A carboxylate group represented by the formula: -OCOR²⁶An acyloxy group represented by -CONR²⁷R²⁸A carbamoyl group represented by -NHSO₂R³³A sulfonamide group represented by the formula: R¹And R², R²And R^Three, R^ThreeAnd R^FourIn the case of forming a ring, a 5- to 6-membered hydrocarbon ring which may be substituted or a 5- to 6-membered heterocyclic ring which may be substituted is preferable.
[0030]
Above all, R¹~ R^FourParticularly preferred as the substituent represented by formula (1) is a linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted, a cyclic alkyl group having 3 to 18 carbon atoms which may be substituted, and 1 to 1 carbon atoms. 12 linear or branched alkoxy groups which may be substituted, 5 to 6-membered saturated heterocyclic groups, 5 to 6-membered heteroaromatic groups, 6 to 18 aryl groups, and 7 to 7 carbon atoms 20 aralkyl groups, linear or branched alkylthio groups having 1 to 12 carbon atoms, halogen atoms, nitro groups, hydroxy groups, -COR²⁰An acyl group represented by -OCOR²⁶An acyloxy group represented by -NR^{twenty one}R^{twenty two}An amino group represented by -COOR^{twenty five}A carboxylate group represented by the formula: -CONR²⁷R²⁸A carbamoyl group represented by -NHSO₂R³³A sulfonamide group represented by¹And R², R²And R^Three, R^ThreeAnd R^FourWhen forming a ring, it is a case where any one of these forms a benzene ring structure.
[0031]
In the general formulas [I] and [II], R^FiveIs a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, a hydroxy group, —NR⁷R⁸, -COR⁹Represents one of the following.
R^FiveExamples of the hydrocarbon group which may be substituted include carbon such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group and n-heptyl group. C 1 -C 18 linear or branched alkyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, etc., C 3-18 cyclic alkyl group, vinyl group, propenyl group, hexenyl group, etc. -18 linear or branched alkenyl groups, cyclopentenyl groups, cyclohexenyl groups, etc., C3-C18 cyclic alkenyl groups, benzyl groups, phenethyl groups, etc., C7-20 aralkyl groups, phenyl groups, tolyl Represents an aryl group having 6 to 18 carbon atoms such as a group, a xylyl group and a mesityl group. The alkyl chain portion and aryl group portion of these groups are the same as the above-mentioned R.¹~ R^FourFurther, the alkyl chain portion may be further substituted with a substituent.
[0032]
R^FiveAs the heterocyclic group which may be substituted, a saturated heterocyclic ring such as 4-piperidyl group, morpholino group, 2-morpholinyl group, piperazyl group, 2-furyl group, 2-pyridyl group, 2-thiazolyl An aromatic heterocyclic ring such as a group or 2-quinolyl group may be used. These may contain a plurality of heteroatoms, may further have a substituent, and may have any bonding position. Preferred structures for the heterocyclic ring are a 5- or 6-membered saturated heterocyclic ring, a 5- or 6-membered monocyclic ring and an aromatic heterocyclic ring thereof.
R^FiveWhen R 1 has an alkyl chain as an optionally substituted hydrocarbon group, R^FourTo form a saturated or unsaturated hydrocarbon ring or a saturated or unsaturated heterocyclic structure, and the cyclic structure may be a single ring or a condensed ring. The number of members in the cyclic structure is not particularly limited, but a hydrocarbon ring and a heterocyclic ring are preferably 5 to 6 membered rings. These preferred cyclic structures are shown below.
[0033]
Embedded image

[0034]
R^Five-NR represented by⁷R⁸R⁷, R⁸Each independently represents a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group.
R⁷, R⁸As R^FiveExamples thereof include the same groups as the hydrocarbon groups and heterocyclic groups exemplified as above, but preferably a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms, and an optionally substituted carbon. These are an aralkyl group having 7 to 20 carbon atoms, an aryl group having 6 to 18 carbon atoms which may be substituted, and a heterocyclic group which may be substituted.
R^Five-COR represented by⁹R in⁹Represents either an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, preferably a linear or branched alkyl group having 1 to 18 carbon atoms, or an optionally substituted 7 to 7 carbon atoms. A aralkyl group having 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms which may be substituted. Preferred R below^FiveAn example of
[0035]
Embedded image

[0036]
Embedded image

[0037]
    The general formula [I]X ^Three Represents an oxygen atomX in [II]^ThreeIs an oxygen atom, a sulfur atom or ═N—R⁶Represents one of the following. X^Three= N-R⁶R in⁶Represents any one of a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, and a hydroxy group, preferably a linear or branched alkyl group having 1 to 18 carbon atoms, An aralkyl group having 7 to 20 carbon atoms which may be substituted and an aryl group having 6 to 20 carbon atoms which may be substituted. Examples of the substituent that these groups may have include the aforementioned R.¹~ R^FourThe same kind as the substituent which the alkyl chain may have can be mentioned.
[0038]
In the general formula [I], X¹Represents an electron-withdrawing group and X²Represents a hydrogen atom or -QY. Here, Q represents a linking group and represents an alkylene group having 1 or 2 carbon atoms, an arylene group, or a heteroarylene group, or directly bonded to Y without these linking groups, that is, a direct bond. Y and X¹And independently represents an electron-withdrawing group.
[0039]
X¹As the electron-withdrawing group represented by Y, those having a positive value for the sigma constants σ (σm and σp, particularly σp) in general Hammett's rule can be cited. Examples of these include halogen-substituted alkyl groups such as cyano group, nitro group, nitroso group, halogen atom, carboxyl group, formyl group, acyl group, carboxylic acid ester group, carbamoyl group, trialkylamino group, trifluoromethyl group, etc. Sulfonic acid group, sulfonic acid ester group, sulfonyl group, sulfamoyl group, sulfinyl group and the like.
These X¹, Y is preferably a cyano group, a nitro group, a halogen-substituted alkyl group, -COR.^TenAn acyl group represented by -COOR¹¹A carboxylate group represented by the formula: -CONR¹²R¹³A carbamoyl group represented by -SOR¹⁶A sulfinyl group represented by -SO₂R¹⁷A sulfonyl group represented by -SO₂NR¹⁸R¹⁹A sulfamoyl group represented by:
[0040]
-COR^TenR of the acyl group represented by^TenRepresents either an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, in which R^TenAs preferred, a linear or branched alkyl group having 1 to 18 carbon atoms which may be substituted, an aralkyl group having 7 to 20 carbon atoms which may be substituted, or an aryl having 6 to 18 carbon atoms which may be substituted A group, a 5- to 7-membered saturated heterocyclic ring that may be substituted, a 5- to 6-membered monocyclic ring that may be substituted, and a heteroaromatic ring that is a double condensed ring thereof. Specific examples include acyl groups such as an acetyl group, a propionyl group, an isovaleryl group, a pivaloyl group, a benzoyl group, a 2-thenoyl group, a 2-furoyl group, and a cyclohexanoyl group.
[0041]
-COOR¹¹R of a carboxylic acid ester group represented by¹¹Represents a hydrocarbon group which may be substituted, a heterocyclic group which may be substituted, preferably a linear or branched alkyl group having 1 to 18 carbon atoms which may be substituted, or a carbon number which may be substituted An aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms which may be substituted, a saturated heterocyclic ring having 5 to 7 members, a monocyclic ring having 5 to 6 members which may be substituted, and a double condensed ring thereof. Heteroaromatic ring. Specific examples include carboxylic acid ester groups such as a methoxycarbonyl group, an ethoxycarbonyl group, an isobutoxycarbonyl group, a phenoxycarbonyl group, a cyclohexyloxycarbonyl group, and a 2-pyridyloxycarbonyl group.
[0042]
-CONR¹²R¹³R of the carbamoyl group represented by¹², R¹³Each independently represents a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, an optionally substituted amino group, an optionally substituted acylamino group, an optionally substituted carbamate group,- COR¹⁴, -COOR¹⁵Represents. Where R¹⁴, R¹⁵Represents an arbitrary substituent, and preferred substituents include a linear or branched alkyl group having 1 to 18 carbon atoms that may be substituted, an aryl group having 6 to 18 carbon atoms that may be substituted, It is also a good amino group.
[0043]
R¹², R¹³As preferable examples, a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, and an optionally substituted carbon number 7 -20 aralkyl groups, 5- to 7-membered saturated heterocycles, optionally substituted 5- to 6-membered monocycles and their bifused heteroaromatic rings, optionally substituted amino groups, -COR¹⁴, -COOR¹⁵Can be given.
-CONR below¹²R¹³The structure of the carbamoyl group represented by these is shown.
[0044]
Embedded image

[0045]
-SOR¹⁶R of the sulfinyl group represented by¹⁶Represents a hydrocarbon group that may be substituted, a heterocyclic group that may be substituted, and preferably a linear or branched alkyl group having 1 to 18 carbon atoms that may be substituted; A good aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms that may be substituted, a saturated heterocyclic ring having 5 to 7 members, a monocyclic ring having 5 to 6 members that may be substituted, and part 2 thereof It is a condensed heteroaromatic ring. Specific examples include the sulfinyl group shown below.
[0046]
Embedded image

[0047]
-SO₂R¹⁷R of a sulfonyl group represented by¹⁷Represents a hydrocarbon group that may be substituted, a heterocyclic group that may be substituted, and preferably a linear or branched alkyl group having 1 to 18 carbon atoms that may be substituted; A good aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 20 carbon atoms that may be substituted, a saturated heterocyclic ring having 5 to 7 members, a monocyclic ring having 5 to 6 members that may be substituted, and part 2 thereof It is a condensed heteroaromatic ring. Specific examples include the sulfonyl groups shown below.
[0048]
Embedded image

[0049]
-SO₂NR¹⁸R¹⁹R of a sulfamoyl group represented by¹⁸, R¹⁹Represents a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, and preferably a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms. , An aryl group having 6 to 18 carbon atoms which may be substituted, an aralkyl group having 7 to 18 carbon atoms which may be substituted, a saturated heterocyclic ring having 5 to 7 members, an optionally substituted 5 to 6 members ring It is a monoaromatic ring and a heteroaromatic ring thereof. Specifically, the sulfamoyl group shown below etc. are mentioned.
[0050]
Embedded image

[0051]
R above^Ten~ R¹⁹Specific examples of the hydrocarbon group which may be substituted and the heterocyclic group which may be substituted include:²⁰~ R³³The same groups as in can be mentioned.
The linking group represented by Q represents a direct bond or an alkylene group having 1 to 2 carbon atoms, an arylene group, or a heteroarylene group. In the case of an alkylene group, the above alkyl chain may have a carbon atom in addition to a hydrogen atom. Even if it has a substituent, it may have an alkyl chain branched therefrom.
When Q represents a 6-membered arylene group or heteroarylene group, the electron-withdrawing group Y is preferably in the ortho or para position with respect to the bond, and when it is a 5-membered heteroarylene group, It is preferable that the bonding portion and the electron-withdrawing group are at the 2-position and the 4-position. A plurality of Ys may be bonded to these linking groups. Moreover, you may have a substituent in places other than Y couple | bonded.
Preferred bonds between these linking groups and electron-withdrawing groups are illustrated below.
[0052]
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[0053]
(G in the figure¹~ G⁶Represents an arbitrary substituent, and Y represents an electron-withdrawing group. )
G¹~ G⁶Preferable examples include nitro group, cyano group, amino group, halogen atom, hydroxy group, alkoxy group, alkylthio group, acyl group, aryl group, aralkyl group, acylamino group, and alkoxycarbonyl group.
[0054]
In the general formula [II], ring A represents a carbocyclic ketone structure or a heterocyclic ketone structure together with> C═O. A carbocyclic ketone and a heterocyclic ketone are -CH in an unsaturated or aromatic ring.₂-Or = CH- is replaced by> C = O. In addition, the ring structure portion of the ring A indicated by the dotted line may have a plurality of> C = O,> C = S,> C = NH, and the like.
The carbocyclic ketone structure and heterocyclic ketone structure formed by ring A may be saturated or unsaturated, and the number of members of the ring is not particularly limited. In the heterocycle, the number of heteroatoms is not particularly limited. The hydrocarbon group in the ring and the hydrogen atom of —NH— constituting the ring may be substituted with any substituent (particularly, an alkyl group or an aryl group is preferable).
These carbocyclic ketone structures and heterocyclic ketone structures may form a condensed ring structure by condensing a further ring with a part of the ring. The ring structure condensed with the cyclic ketone structure may be a hydrocarbon ring or a heterocyclic ring, but is preferably a benzene ring or a 5- to 6-membered heteroaromatic ring.
The structure shown by the cyclic ketone is illustrated below.
[0055]
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[0056]
Preferable examples of the carbocyclic ketone structure and heterocyclic ketone structure formed by ring A include a 5- or 6-membered saturated hydrocarbon ring or a 5- or 6-membered saturated or unsaturated heterocyclic ring. .
The compounds represented by the general formulas [I] and [II] have a molecular weight of preferably 1000 or less, particularly preferably 700 or less.
Preferred examples of the compounds represented by the general formulas [I] and [II] include the following.
[0057]
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[0058]
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[0059]
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[0060]
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[0061]
Since the dyes composed of the compounds represented by the above general formulas [I] and [II] of the present invention are excellent in thin film formation when forming a recording layer from a solution containing the dyes, for example, It is extremely useful as a dye for use in the recording layer of an optical recording medium. In addition, the dye of the present invention has a recording layer containing the dye having an absorption intensity suitable for recording / reproducing with a laser beam in a shorter wavelength (350 nm to 500 nm) region. It is extremely useful as a dye for use in an optical recording medium for reproduction.
[0062]
The optical recording medium of the present invention is basically composed of a substrate and a recording layer containing the dye compound, and further, if necessary, an undercoat layer, a reflective layer, a protective layer, etc. on the substrate. It may be provided.
As an example of a preferable layer structure, a high reflectivity medium in which a recording layer is provided on a substrate, and a metal reflective layer such as gold, silver, and aluminum and a protective layer are provided on the recording layer. Hereinafter, the optical recording medium of the present invention will be described with reference to the medium having this structure.
[0063]
The material of the substrate in the optical recording medium of the present invention may basically be transparent to the wavelengths of recording light and reproducing light.
Examples of such materials include acrylic resins, methacrylic resins, polycarbonate resins, polyolefin resins (particularly amorphous polyolefins), polyester resins, polystyrene resins, epoxy resins, and the like, and glass materials. A glass having a resin layer made of a radiation curable resin such as a photocurable resin can be used.
[0064]
From the viewpoints of high productivity, cost, moisture absorption resistance, etc., injection molded polycarbonate is preferable, and from the viewpoints of chemical resistance, moisture absorption resistance, etc., amorphous polyolefin is preferable. Moreover, a glass substrate is preferable from the viewpoint of high-speed response.
A resin substrate or a resin layer may be provided in contact with the recording layer, and guide grooves or pits for recording / reproducing light may be provided on the resin substrate or resin layer. When the guide groove is spiral, the groove pitch is preferably about 0.2 to 1.2 μm.
[0065]
A recording layer containing the compound of the present invention is formed on a substrate or an undercoat layer as necessary.
As a method for forming the recording layer, a generally used thin film forming method such as a vacuum deposition method, a sputtering method, a doctor blade method, a casting method, a spin coating method, or an immersion method can be given. The spin coating method is preferable from the viewpoint of mass productivity and cost. Further, from the viewpoint that a recording layer having a uniform thickness can be obtained, a vacuum deposition method or the like is preferable to a coating method.
In the case of film formation by a spin coating method, the number of rotations is preferably 500 to 15000 rpm, and after spin coating, a treatment such as heating or solvent vapor may be performed in some cases.
[0066]
The coating solvent for forming the recording layer by a coating method such as a doctor blade method, a casting method, a spin coating method, or a dipping method may be any solvent that does not attack the substrate and is not particularly limited. For example, ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone; cellosolv solvents such as methyl cellosolve and ethyl cellosolve; chain hydrocarbon solvents such as n-hexane and n-octane Cyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, tert-butylcyclohexane and cyclooctane; fluoroalkyl alcohols such as tetrafluoropropanol, octafluoropentanol and hexafluorobutanol Solvents; hydroxycarboxylic acid ester solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; amino-substituted alcohol solvents such as 2-dimethylaminoethanol and 2-diethylaminoethanol It is.
[0067]
In the case of the vacuum deposition method, for example, the compound of the present invention and, if necessary, recording layer components such as other dyes and various additives are put in a crucible installed in the vacuum vessel, and the inside of the vacuum vessel is appropriately vacuumed. 10 with a pump^-2-10^-FiveAfter evacuating to about Pa, the crucible is heated to evaporate the recording layer components and vapor deposited on the substrate placed facing the crucible to form the recording layer.
[0068]
In addition, the recording layer has a transition metal chelate compound (for example, acetylacetonate chelate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, etc.) as a singlet oxygen quencher to improve the stability and light resistance of the recording layer. ) And the like, and a recording sensitivity improver such as a metal compound may be contained for improving the recording sensitivity. Here, the metal compound means a compound in which a metal such as a transition metal is contained in the compound in the form of atoms, ions, clusters, etc., for example, ethylenediamine complex, azomethine complex, phenylhydroxyamine complex, phenanthroline complex, Organic metal compounds such as dihydroxyazobenzene complex, dioxime complex, nitrosoaminophenol complex, pyridyltriazine complex, acetylacetonate complex, metallocene complex and porphyrin complex can be mentioned. Although it does not specifically limit as a metal atom, It is preferable that it is a transition metal.
[0069]
Furthermore, other types of pigments can be used in combination as necessary. Other dyes are not particularly limited as long as they have appropriate absorption mainly in the laser wavelength region for recording. In addition, multiple dyes suitable for recording with a near-infrared laser of a wavelength selected from 770 to 830 nm such as CD-R and a red laser selected from 620 to 690 nm such as DVD-R are used in combination. An optical recording medium corresponding to recording with a laser beam in a wavelength region may be used.
Other dyes include metal-containing azo dyes, phthalocyanine dyes, naphthalocyanine dyes, cyanine dyes, azo dyes, squarylium dyes, metal-containing indoaniline dyes, triarylmethane dyes, merocyanine dyes, Examples include azulenium dyes, naphthoquinone dyes, anthraquinone dyes, indophenol dyes, xanthene dyes, oxazine dyes, and pyrylium dyes.
[0070]
Furthermore, a binder, a leveling agent, an antifoaming agent, etc. can also be used together as needed. Preferable binders include polyvinyl alcohol, polyvinyl pyrrolidone, nitrocellulose, cellulose acetate, ketone resin, acrylic resin, polystyrene resin, urethane resin, polyvinyl butyral, polycarbonate, polyolefin and the like.
The film thickness of the recording layer is not particularly limited because it varies depending on the recording method and the like, but is usually 50 to 300 nm.
[0071]
A reflective layer may be formed on the recording layer, and the thickness thereof is preferably 50 to 300 nm. As a material of the reflective layer, a material having a sufficiently high reflectivity at the wavelength of the reproduction light, for example, Au, Al, Ag, Cu, Ti, Cr, Ni, Pt, Ta, Cr, and Pd metal alone or in an alloy It is possible to use. Among these, Au, Al, and Ag have high reflectivity and are suitable as a material for the reflective layer. In addition to these as main components, the following components may be included as other components. Examples of other components are Mg, Se, Hf, V, Nb, Ru, W, Mn, Re, Fe, Co, Rh, Ir, Cu, Zn, Cd, Ga, In, Si, Ge, Te, Pb , Po, Sn, Bi, Nd, Ta, Ti, Pt, Pd, and other metals and metalloids. Among these, those containing Ag as a main component are particularly preferred because of low cost, high reflectivity, and when a print receiving layer described later is provided, a white and beautiful ground color can be obtained. Here, the main component means one having a content of 50% or more.
[0072]
It is also possible to form a multilayer film by alternately stacking a low refractive index thin film and a high refractive index thin film using a material other than metal, and use it as a reflective layer.
Examples of the method for forming the reflective layer include sputtering, ion plating, chemical vapor deposition, and vacuum vapor deposition. In addition, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or below the reflective layer in order to improve reflectivity, improve recording characteristics, and improve adhesion.
The thickness of the reflective layer is usually about 40 to 200 nm.
[0073]
The material for the protective layer formed on the reflective layer is not particularly limited as long as it protects the reflective layer from external force. Examples of the organic material include thermoplastic resins, thermosetting resins, electron beam curable resins, and UV curable resins. Examples of inorganic substances include silicon oxide, silicon nitride, and MgF.₂, SnO₂Etc.
A thermoplastic resin, a thermosetting resin, etc. can be formed by dissolving in an appropriate solvent to prepare a coating solution, and applying and drying the coating solution. The UV curable resin can be formed by preparing a coating solution as it is or by dissolving it in a suitable solvent, and then applying the coating solution and curing it by irradiating with UV light. As the UV curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or in combination, and may be used not only as a single layer but also as a multilayer film.
[0074]
As a method for forming the protective layer, a coating method such as a spin coating method and a casting method, a sputtering method, a chemical vapor deposition method, and the like are used as in the recording layer. Among these, a spin coating method is preferable.
The thickness of the protective layer is generally in the range of 0.1 to 100 μm, but in the present invention, 3 to 30 μm is preferable.
[0075]
The above description has been made by taking as an example an optical recording medium having a basic layer structure in which a substrate / recording layer / reflective layer / protective layer are laminated in this order, and performing recording / reproduction with laser light irradiated through the substrate. However, any layer may be provided between these layers as long as the characteristics of the present invention are not impaired.
Further, the substrate may be further bonded to the protective layer or the reflective layer without providing the protective layer via an adhesive layer or the like. The substrate may be the substrate itself without any layers, or may have an arbitrary layer on the bonding surface or the opposite surface. Two substrates having at least a recording layer may be prepared and bonded so that the recording layers face each other, whereby an optical recording medium capable of recording / reproducing on both sides may be used.
[0076]
Furthermore, the optical recording medium of the present invention has a basic layer structure in which a substrate / reflective layer / recording layer / protective film is sequentially laminated, and recording / reproduction is performed by laser light irradiated through the protective film. It may be. This protective film may be a film or a sheet-like material bonded together with an adhesive, or may be formed by applying a film-forming coating solution in the same manner as the protective layer described above. Also in the case of such a basic layer configuration, an arbitrary layer may be provided between the above-described layers as long as the characteristics of the present invention are not impaired.
[0077]
By the way, as one means for increasing the recording density of the optical recording medium, it has been proposed to increase the numerical aperture of the objective lens to reduce the light spot focused on the information recording surface. When the numerical aperture is increased, the aberration of the light spot that is collected increases due to the influence of the warp of the disk, and there is a problem that a good recording / reproducing signal cannot be stably obtained.
In order to reduce the aberration caused by the warp of the medium, for example, the recording / reproducing laser beam has a basic layer structure in which a substrate / recording layer / reflective layer / protective layer is laminated in this order. It is preferable that the thickness of the transparent substrate passing through is reduced to about 0.1 mm, or recording / reproduction is performed through the protective coating on an optical recording medium in which the substrate / reflective layer / recording layer / protective coating is sequentially laminated. The thickness of the protective coating is usually about 0.1 μm to 0.3 mm, preferably about 0.1 μm to 200 μm.
In any of the above stacked media, print acceptance that can be filled in (printed) by various printers such as ink jet and thermal transfer, or various writing tools, on the surface other than the incident surface of recording / reproducing light as required. A layer may be provided.
[0078]
The laser beam used for the optical recording medium of the present invention is preferably as short as possible for high-density recording, but a laser beam of 350 to 530 nm is particularly preferable. Typical examples of such laser light include laser light having center wavelengths of 405 nm, 410 nm, and 515 nm.
An example of laser light having a wavelength in the range of 350 to 530 nm can be obtained by using a high-power semiconductor laser of 405 nm, 410 nm blue or 515 nm blue-green, but, for example, (a) the fundamental oscillation wavelength is Either a semiconductor laser capable of continuous oscillation of 740 to 960 nm, or (b) a solid laser capable of continuous oscillation excited by a semiconductor laser and having a fundamental oscillation wavelength of 740 to 960 nm is generated by a second harmonic generation element (SHG). It can also be obtained by wavelength conversion.
[0079]
The SHG may be any piezoelectric element that lacks inversion symmetry, but KDP, ADP, BNN, KN, LBO, a compound semiconductor, and the like are preferable. As a specific example of the second harmonic, in the case of a semiconductor laser having a fundamental oscillation wavelength of 860 nm, a harmonic of 430 nm, and in the case of a solid-state laser pumped by a semiconductor laser, Cr-doped LiSrAlF₆430 nm of the double wave from the crystal (basic oscillation wavelength 860 nm).
[0080]
Recording on the optical recording medium of the present invention obtained as described above is performed by irradiating the recording layer provided on both sides or one side of the substrate with laser light focused to about 0.4 to 0.6 μm. In the portion irradiated with the laser beam, thermal deformation of the recording layer such as decomposition, heat generation and dissolution due to absorption of laser beam energy occurs, and the optical characteristics change.
Reproduction of recorded information is performed by reading the difference in reflectance between the portion where the change in optical characteristics has occurred and the portion where the change has not occurred, with laser light.
[0081]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples unless it exceeds the gist.
[Synthesis example]
The method for synthesizing the compounds represented by the general formulas [I] and [II] is not particularly limited, but as a general production method, Tetrahedron, Vol. As described in Soc., Vol. 67 (1990), p490, it is known to be obtained by reacting an isatin derivative with a compound having active methylene.
[0082]
Example 1
(A) Production example
2.94 g (20 mmol) of isatin and 2.49 g (22 mmol) of cyanoacetic acid ethyl ester were stirred and dissolved in 20 ml of ethanol, 2 drops of piperidine were added, and the mixture was refluxed in an oil bath for 4 hours. The reaction solution was cooled to room temperature, the precipitated solid was filtered, and the solid was filtered off to obtain 3.93 g (yield: 81.1%) of the compound represented by Exemplary Compound (1).
This compound had a maximum absorption wavelength (λmax) in chloroform of 338.5 nm and a molar extinction coefficient of 11,100.
[0083]
(B) Recording medium example
The aforementioned exemplary compound (1) was dissolved in octafluoropentanol to prepare 1.0 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes. The maximum absorption wavelength (λmax) of this coating film was 339.0 nm.
[0084]
Example 2
(A) Production example
1.92 g (10 mmol) of 5-nitroisatin and 1.24 g (11 mmol) of cyanoacetic acid ethyl ester were stirred and dissolved in 10 ml of ethanol, 1 drop of piperidine was added, and the mixture was refluxed in an oil bath for 4 hours. The reaction solution was cooled to room temperature, the precipitated solid was filtered, and the solid was filtered off to obtain 2.14 g (yield 74.5%) of the compound represented by the exemplified compound (2).
This compound had a maximum absorption wavelength (λmax) in chloroform of 307.0 nm and a molar extinction coefficient of 21,300.
[0085]
(B) Recording medium example
The aforementioned exemplary compound (2) was dissolved in octafluoropentanol to prepare 1.0 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes. The maximum absorption wavelength (λmax) of this coating film was 308 nm.
[0086]
Example 3
(A) Production example
2.42 g (10 mmol) of the above exemplified compound (2) was added to 10 ml of acetic anhydride, this solution was refluxed in an oil bath for 4 hours, cooled to room temperature, and then added dropwise to 100 ml of water. The precipitated solid was separated by filtration to obtain 2.45 g (yield 86%) of the compound represented by the exemplified compound (4).
This compound had a maximum absorption wavelength (λmax) in chloroform of 341.5 nm and a molar extinction coefficient of 10,300.
[0087]
(B) Recording medium example
The aforementioned exemplary compound (4) was dissolved in octafluoropentanol to prepare 1.0 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes. The maximum absorption wavelength (λmax) of this coating film was 342.0 nm.
[0088]
Example 4
(A) Production example
2.94 g (20 mmol) of isatin and 1.45 g (22 mmol) of malononitrile were dissolved in 20 ml of ethanol with stirring, 2 drops of piperidine were added, and the mixture was refluxed in an oil bath for 4 hours. The reaction solution was cooled to room temperature, the precipitated solid was filtered, and the solid was filtered off to obtain 3.78 g (yield 96.8%) of the compound represented by the exemplified compound (3).
This compound had a maximum absorption wavelength (λmax) in chloroform of 351.0 nm and a molar extinction coefficient of 13,200.
[0089]
(B) Recording medium example
The aforementioned exemplary compound (3) was dissolved in methyl lactate to prepare 2.0 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes. The maximum absorption wavelength (λmax) of this coating film was 351.0 nm.
[0090]
Example 5
(A) Production example
1.95 g (10 mmol) of the above exemplified compound (4) was added to 10 ml of acetic anhydride, this solution was refluxed in an oil bath for 4 hours, cooled to room temperature, and then added dropwise to 100 ml of water. The precipitated solid was filtered off to obtain 1.98 g (yield: 83.5%) of the compound represented by the exemplary compound (5).
This compound had a maximum absorption wavelength (λmax) in chloroform of 358.0 nm and a molar extinction coefficient of 13,100.
[0091]
(B) Recording medium example
The above exemplified compound (5) was dissolved in octafluoropentanol to prepare 1.0 wt%. A solution obtained by filtering this was dropped onto an injection-molded polycarbonate resin substrate having a diameter of 120 mm and a thickness of 1.2 mm, applied by a spinner method, and dried at 100 ° C. for 30 minutes. The maximum absorption wavelength (λmax) of this coating film was 371.0 nm.
[0092]
On this coating film prepared as described above, for example, a silver film is formed by sputtering or the like to form a reflective layer, and further, UV curable resin is applied by spin coating or the like and cured by UV irradiation to protect it. A layer can be formed to provide an optical recording medium. It is apparent that this optical recording medium can be recorded and reproduced by a laser having a wavelength of 350 nm to 530 nm, for example, a semiconductor laser having a central wavelength of 405 nm, from the value of λmax of the coating film.
[0093]
【The invention's effect】
The solution containing the dye compound of the present invention can form a coating film having absorption suitable for recording / reproduction with a laser beam with a short wavelength and is excellent in film formability. The recording medium having the recording layer used is useful as an optical recording medium for recording / reproducing corresponding to a short wavelength laser.

Claims (12)

An optical recording medium having a recording layer capable of recording or reproducing information by a laser on a substrate, wherein the recording layer contains a compound represented by the following general formula [I].

{Wherein R ^{1 to} R ⁴ represent a hydrogen atom or an arbitrary substituent, and at least two adjacent substituents of R ^{1 to} R ⁴ may combine to form a hydrocarbon ring or a heterocyclic structure. The hydrocarbon ring and the hetero ring may have a substituent. X ¹ represents an electron-withdrawing group, and X ² represents a hydrogen atom or -QY. (Q represents a direct bond, an alkylene group having 1 or 2 carbon atoms, an arylene group, or a heteroarylene group, and Y represents an electron-withdrawing group. The alkylene group, the arylene group, and the heteroarylene group are optional in addition to Y. may have a substituent.) X ³ represents an oxygen atom. R ⁵ is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, a hydroxy group, —NR ⁷ R ⁸ (R ⁷ and R ⁸ are each independently a hydrogen atom, substituted Represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted.), Or —COR ⁹ (R ⁹ represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted.) R ⁵ may be bonded to R ⁴ to form an optionally substituted hydrocarbon ring or an optionally substituted heterocyclic structure. } General formula [ I ] R ¹ ~ R ^Four Represents a hydrogen atom or an arbitrary substituent, and X ² Represents a hydrogen atom or -QY (Q represents a direct bond, Y represents an electron-withdrawing group), R ^Five Is a hydrogen atom or -COR ⁹ (R ⁹ Represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted. The optical recording medium according to claim 1, wherein: In the general formula [I], the electron-withdrawing groups X ¹ and Y are each independently a halogen-substituted alkyl group, a cyano group, a nitro group, —CO—R ¹⁰ (where R ¹⁰ is an optionally substituted hydrocarbon group, a substituted And -COOR ¹¹ (R ¹¹ represents a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group), -CONR ¹² R ¹³ [R ^12. , R ¹³ are each independently a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, an optionally substituted amino group, an optionally substituted acylamino group, an optionally substituted carbamate Group, —COR ¹⁴ , —COOR ¹⁵ (R ¹⁴ and R ¹⁵ are optional substituents). ], -SOR ¹⁶ (R ¹⁶ represents an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group.)-SO ₂ R ¹⁷ (R ¹⁷ represents an optionally substituted hydrocarbon group or an optionally substituted hydrocarbon group; -SO ₂ NR ¹⁸ R ¹⁹ (R ¹⁸ and R ¹⁹ each independently represents a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group. Q represents a direct bond, a phenylene group, or a 5- to 6-membered heteroarylene group (the phenylene group and the 5- to 6-membered heteroarylene group have a substituent in addition to Y). the optical recording medium according to claim 1 or 2, characterized in that represents a good.) also. In the general formula [I], R ^{1 to} R ⁴ are each independently a linear or branched alkyl group having 1 to 18 carbon atoms that may be substituted, or a cyclic alkyl group having 3 to 18 carbon atoms that may be substituted. , An optionally substituted linear or branched alkenyl group having 2 to 18 carbon atoms, an optionally substituted cyclic alkenyl group having 3 to 18 carbon atoms, an optionally substituted heterocyclic group, and an optionally substituted carbon An aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 24 carbon atoms that may be substituted, a linear or branched alkoxy group having 1 to 18 carbon atoms that may be substituted, and 3 to 3 carbon atoms that may be substituted 18 linear or branched alkenyloxy groups, optionally substituted linear or branched alkylthio groups having 1 to 18 carbon atoms, halogen atoms, nitro groups, nitroso groups, cyano groups, isocyano groups, cyanato groups, isocyanato groups , Thioshi Anat group, isothiocyanato group, mercapto group, hydroxy group, hydroxyamino group, a sulfonic acid group, formyl group, carboxyl group, acyl group represented by -COR ^20, amino group represented by -NR ²¹ R ^22, -NHCOR An acylamino group represented by ²³ , a carbamate group represented by -NHCOOR ²⁴ , a carboxylic acid ester group represented by -COOR ²⁵ , an acyloxy group represented by -OCOR ²⁶ , and a carbamoyl represented by -CONR ²⁷ R ²⁸ Group, a sulfonyl group represented by —SO ₂ R ²⁹ , a sulfamoyl group represented by —SO ₂ NR ³⁰ R ³¹ , a sulfonate group represented by —SO ₃ R ³² , and a —NHSO ₂ R ³³ (R ²⁰ , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁹ , R ³² , R ³³ are optionally substituted hydrocarbon groups, or may be substituted) R ²¹ , R ²² , R ²⁷ , R ²⁸ , R ³⁰ , and R ^{31 each} represent a hydrogen atom, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group. ), R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ are each independently bonded to each other and may be substituted, a 5- to 7-membered hydrocarbon ring, or may be substituted The optical recording medium according to any one of claims 1 to 3, wherein a good 5- to 6-membered heterocyclic ring may be formed. In the general formula [I], R ^{1 to} R ⁴ are each independently a linear or branched alkyl group having 1 to 12 carbon atoms that may be substituted, or a cyclic alkyl group having 3 to 18 carbon atoms that may be substituted. A C2-C12 linear or branched alkenyl group which may be substituted, a 5- or 6-membered saturated heterocyclic group, a 5- or 6-membered monocyclic or bi-fused heteroaromatic group, substitution Aryl group having 6 to 18 carbon atoms which may be substituted, aralkyl group having 7 to 20 carbon atoms which may be substituted, linear or branched alkoxy group having 1 to 12 carbon atoms which may be substituted, Good linear or branched alkylthio group having 1 to 12 carbon atoms, halogen atom, nitro group, cyano group, mercapto group, hydroxy group, acyl group represented by —COR ²⁰ , amino represented by —NR ²¹ R ²² group, an acylamino group represented by -NHCOR ^23, Carbamate group represented by NHCOOR ^24, a carboxylate group represented by -COOR ^25, acyloxy group represented by -OCOR ^26, a carbamoyl group represented by -CONR ²⁷ R ^28, Table with -NHSO ₂ R ³³ (However, R ²⁰ , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ³³ , R ²¹ , R ²² , R ²⁷ , R ²⁸ have the same meanings as in claim 4 ). , R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ are each independently bonded to each other, and may be an optionally substituted 5- to 7-membered hydrocarbon ring, or an optionally substituted 5 the optical recording medium according to any one of claims 1 to 3, characterized in that may form a heterocyclic ring of 6-membered ring. In the general formula [I], R ⁵ is a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms, an optionally substituted cyclic alkyl group having 3 to 18 carbon atoms, An aryl group having 6 to 24 carbon atoms, an aralkyl group having 7 to 20 carbon atoms that may be substituted, a heterocyclic group that may be substituted, a cyano group, a hydroxy group, —NR ⁷ R ⁸ (R ⁷ , R ⁸ each independently represents a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms, an optionally substituted aryl group having 6 to 24 carbon atoms, or an optionally substituted carbon number 7 20 aralkyl group, representative of the optionally substituted heterocyclic ^{group), -. COR 9 (R} 9 is a straight-chain or branched alkyl group having 1 to 18 carbon atoms which may be substituted, may be substituted Aryl group having 6 to 24 carbon atoms, optionally substituted 7 to 2 carbon atoms Aralkyl group, an optical recording medium according to any one of claims 1 to 5, characterized in that represent a.) Representing the optionally substituted heterocyclic group. An optical recording medium provided with a recording layer capable of recording or reproducing information by a laser on a substrate, wherein the recording layer contains a compound represented by the following general formula [II] .

{Wherein R ^{1 to} R ⁴ represent a hydrogen atom or an arbitrary substituent, and at least two adjacent substituents of R ^{1 to} R ⁴ may combine to form a hydrocarbon ring or a heterocyclic structure. The hydrocarbon ring and the hetero ring may have a substituent. Ring A represents a carbocyclic ketone ring or heterocyclic ketone ring which may have a substituent together with> C═O. X ³ represents an oxygen atom, a sulfur atom or ═N—R ⁶ (R ⁶ represents a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group or a hydroxy group.) . R ⁵ is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted heterocyclic group, a cyano group, a hydroxy group, —NR ⁷ R ⁸ (R ⁷ and R ⁸ are each independently a hydrogen atom, substituted Represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted.), Or —COR ⁹ (R ⁹ represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted.) R ⁵ may be bonded to R ⁴ to form an optionally substituted hydrocarbon ring or an optionally substituted heterocyclic structure. } In the general formula [II], the ring A is a 5- to 6-membered carbocyclic ketone ring which may be substituted, or a 5- to 6-membered heterocyclic ketone ring which may be substituted. The optical recording medium according to claim 7 . In the general formula [II], R ^{1 to} R ⁴ are each independently a linear or branched alkyl group having 1 to 18 carbon atoms which may be substituted, or a cyclic alkyl group having 3 to 18 carbon atoms which may be substituted. , An optionally substituted linear or branched alkenyl group having 2 to 18 carbon atoms, an optionally substituted cyclic alkenyl group having 3 to 18 carbon atoms, an optionally substituted heterocyclic group, and an optionally substituted carbon An aryl group having 6 to 18 carbon atoms, an aralkyl group having 7 to 24 carbon atoms that may be substituted, a linear or branched alkoxy group having 1 to 18 carbon atoms that may be substituted, and 3 to 3 carbon atoms that may be substituted 18 linear or branched alkenyloxy groups, optionally substituted linear or branched alkylthio groups having 1 to 18 carbon atoms, halogen atoms, nitro groups, nitroso groups, cyano groups, isocyano groups, cyanato groups, isocyanato groups , Thioshi Isocyanato group, an isothiocyanato group, mercapto group, hydroxy group, hydroxyamino group, a sulfonic acid group, formyl group, carboxyl group, acyl group represented by -COR ^20, amino group represented by -NR ²¹ R ^22, -NHCOR An acylamino group represented by ²³ , a carbamate group represented by -NHCOOR ²⁴ , a carboxylic acid ester group represented by -COOR ²⁵ , an acyloxy group represented by -OCOR ²⁶ , and a carbamoyl represented by -CONR ²⁷ R ²⁸ Group, a sulfonyl group represented by —SO ₂ R ²⁹ , a sulfamoyl group represented by —SO ₂ NR ³⁰ R ³¹ , a sulfonate group represented by —SO ₃ R ³² , and a —NHSO ₂ R ³³ that represents a sulfonamido group ^{(R 20, R 23, R} 24, R 25, R 26, R 29, R 32, R 33 is optionally substituted hydrocarbon group or an optionally substituted, A heterocyclic group, ^{R 21, R 22, R 27} , R 28, R 30, R 31 is a hydrogen atom, an optionally substituted hydrocarbon group, one of the heterocyclic group which may be substituted. ), R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ are each independently bonded to each other, and may be a 5- to 7-membered hydrocarbon ring, or may be substituted. The optical recording medium according to claim 7 or 8 , wherein a 5- to 6-membered heterocyclic ring may be formed. In the general formula [II], R ^{1 to} R ⁴ are each independently a linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted, or a cyclic alkyl group having 3 to 18 carbon atoms which may be substituted. A C2-C12 linear or branched alkenyl group which may be substituted, a 5- or 6-membered saturated heterocyclic group, a 5- or 6-membered monocyclic or bi-fused heteroaromatic group, substitution Aryl group having 6 to 18 carbon atoms which may be substituted, aralkyl group having 7 to 20 carbon atoms which may be substituted, linear or branched alkoxy group having 1 to 12 carbon atoms which may be substituted, Good linear or branched alkylthio group having 1 to 12 carbon atoms, halogen atom, nitro group, cyano group, mercapto group, hydroxy group, acyl group represented by —COR ²⁰ , amino represented by —NR ²¹ R ²² group, an acylamino group represented by -NHCOR ^23, - Carbamate group represented by NHCOOR ²⁴ , carboxylic acid ester group represented by -COOR ²⁵ , acyloxy group represented by -OCOR ²⁶ , carbamoyl group represented by -CONR ²⁷ R ²⁸ , and -NHSO ₂ R ³³ (However, R ²⁰ , R ²³ , R ²⁴ , R ²⁵ , R ²⁶ , R ³³ , R ²¹ , R ²² , R ²⁷ , R ²⁸ have the same meanings as in claim 4 ). , R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ are each independently bonded to each other, and may be an optionally substituted 5- to 7-membered hydrocarbon ring, or an optionally substituted 5 The optical recording medium according to claim 7 or 8 , wherein a heterocyclic ring having 6 to 6 members may be formed. In the general formula [II], R ⁵ is a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms, an optionally substituted cyclic alkyl group having 3 to 18 carbon atoms, An aryl group having 6 to 24 carbon atoms, an aralkyl group having 7 to 20 carbon atoms that may be substituted, a heterocyclic group that may be substituted, a cyano group, a hydroxy group, —NR ⁷ R ⁸ (R ⁷ , R ⁸ each independently represents a hydrogen atom, an optionally substituted linear or branched alkyl group having 1 to 18 carbon atoms, an optionally substituted aryl group having 6 to 24 carbon atoms, or an optionally substituted carbon number 7 20 aralkyl group, representative of the optionally substituted heterocyclic ^{group), -. COR 9 (R} 9 is a straight-chain or branched alkyl group having 1 to 18 carbon atoms which may be substituted, may be substituted Aryl group having 6 to 24 carbon atoms, optionally substituted 7 to 20 carbon atoms The optical recording medium according to claim 7 , wherein the aralkyl group is an optionally substituted heterocyclic group. Optical recording method wavelength using a laser beam of 350Nm～530nm, and performs recording of information with respect to an optical recording medium according to claim 1-11.